COVID-19 Information & Resources
101 Science-Based Tips That Could Save Your Life.

What are viruses associated with respiratory infections?

"Viruses associated with respiratory infections" refer to the viruses that invade and proliferate in the epithelial cells of the respiratory tracts that could cause respiratory and systemic symptoms.

What are the common viruses associated with respiratory infections?

Viruses from the family Orthomyxoviridae (influenza viruses), the family Paramyxoviridae (paramyxoviruses, respiratory syncytial virus, measles virus, mumps virus, Hendra virus, Nipah virus and human metapneumovirus), the family Togaviridae (Rubella virus), the family Picornaviridae (rhinovirus), and the family Coronaviridae (SARS coronavirus) are the common respiratory viruses. In addition, adenoviru reovirus, coxsackie virus, ECHO virus, herpes virus, etc. can also cause infectious respiratory diseases.

What are coronaviruses?

Coronavirus are unsegmented single-stranded positive-strand RNA viruses. They belong to the order Nidovirales, the family Coronaviridae, and the subfamily Orthocoronavirinae, which is divided into α, β, γ, and δ genera according to their serotypic and genomic characteristics. Coronaviruses belong to the genus Coronavirus of the family Coronaviridae. It is named after the wreath-shaped protrusions on the envelope of the virus.

What are the shape and structure of coronaviruses?

Coronaviruses have an envelope encasing the RNA genome), and the virions (the whole viruses) are round or oval, often polymorphic, with a diameter of 50 to 200 nm. The novel coronavirus is 60 to 140 nm in diameter. The spike protein is located on the surface of the virus and forms a rod-like structure. As one of the main antigenic proteins of the virus, the spike protein is the main structure used for typing. The nucleocapsid protein encapsulates the viral genome and can be used as a diagnostic antigen.

How are coronaviruses classified?

Most coronaviruses infect animals. Currently, three types of coronaviruses have been isolated from humans: Human Coronaviruses 229E, OC43, and SARS coronavirus (SARS-CoV). There are 6 types of coronaviruses previously known to infect humans. 229E and NL63 (of alphacoronaviruses), OC43 (of betacoronaviruses), HKU1, Middle East Respiratory Syndrome Coronavirus (MERS-CoV), and Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV).

Recently, a novel coronavirus was isolated from the lower respiratory tract of patients in “Wuhan, who were suffering from pneumonia due to unknown causes (The World Health Organization (WHO) called it 2019-nCoV while the International Committee on the Taxonomy of Viruses (ICTV) named it SARS-CoV-2. It was subsequently confirmed that the virus is capable of human-to-human transmission.

This novel coronavirus is very similar in terms of the genome sequences to six previously discovered coronaviruses. An analysis of their genetic sequence homology revealed that the new virus has many similarities with SARS-CoV. This novel coronavirus is now classified as a beta-coronavirus.

Which wild animals carry coronaviruses?

Many wild animals carry pathogens and are potential transmission vectors of certain contagious diseases. Bats, civets, badgers, bamboo rats, and wild camels, etc. are known hosts of coronaviruses.

The outbreak of novel coronavirus pneumonia originated in Wuhan has many similarities to the SARS outbreak in Guangdong back in 2003: both began in the winter; the initial cases were traced to contacts with fresh, live animals in a market; both were caused by a previously unknown coronavirus.

Due to the similarity of the genomic sequences between the novel coronavirus and a coronavirus found in bats, which is 85% or higher, it is speculated that bats are the natural hosts of the novel coronavirus. Like the SARS coronavirus that caused the “outbreak in 2003, the novel coronavirus is likely to have intermediate hosts between bats and humans yet unknown to us.

Therefore, one should refrain from consumption of uninspected wild animals or uncooked food such as meat sold by roadside sellers.

How do coronaviruses transmit from animals to humans?

Many coronaviruses that infect humans could be found in bats, which are natural reservoirs of coronaviruses. Bats are likely to be the original host of the novel coronavirus. Transmission from bats to humans might have occurred after mutation via an intermediate host(s). The genomic sequence analysis showed a more than 85% homology between the novel coronavirus and a coronavirus in bats. However, there are several other possible intermediate hosts between bats and humans, which have not been confirmed yet. Animal-to-human or human-to-human transmission relies mainly on two routes: contacts and droplets.

The coronaviruses that are currently known to cause pneumonia in humans include HKU1, SARS-CoV, MERS-CoV, and 2019-nCoV.

How resilient are coronaviruses in different environments?

Viruses generally can survive for several hours on smooth surfaces. If the temperature and humidity permit, they can survive for several days. The novel coronavirus is sensitive to ultraviolet rays and heat. Sustained heat at 132.8ºF for 30 minutes, ether, 75% alcohol, chlorine-containing disinfectants, peracetic acid, chloroform, and other lipid solvents can effectively inactivate the virus. Chlorhexidine (also known as chlorhexidine gluconate) also effectively inactivates the virus.

The survival time of the novel coronavirus 2019-nCoV at different environmental temperatures is as follows.

How virulent is SARS-CoV-2, and what is the incubation period?

Common coronaviruses mainly infect adults or older children, causing the common cold. Some strains can cause diarrhea in adults. These viruses are mainly transmitted by droplets and aerosols, and can also be spread via the fecal-oral route. The incidence of coronavirus infection is prevalent in winter and spring.

Incubation Period: The time from exposure to symptom onset varies by variant:

• Original strain: Median incubation of 5-6 days, ranging from 2-14 days
• Delta variant: Shorter incubation, median around 4 days
• Omicron variant: Even shorter, median around 3 days (range 2-5 days)

Virulence: To measure the harm caused by a virus, both infectivity and severity must be considered. SARS-CoV-2 is highly infectious. The severity of illness varies significantly:

• Many infections are asymptomatic or cause mild illness
• Severe illness and death rates have decreased due to vaccines, treatments, and population immunity
• Risk remains higher for elderly, immunocompromised, and those with underlying conditions
• Different variants have shown different patterns of severity (e.g., Omicron generally causes less severe disease than Delta)

Can humans develop immunity to 2019-nCoV?

Scientific data on the level and the duration of protective immune antibodies produced in patients after infection of the novel coronavirus remain scarce. In general, the protective antibodies (immunoglobulin G, IgG) against a virus can be produced two weeks or so after an infection, and may exist for several weeks to many years, preventing re-infection of the same virus after recovery. Currently efforts are underway to test whether recently recovered from 2019-nCoV infection carry protective antibodies in the blood.

What is Severe Acute Respiratory Syndrome (SARS)?

Severe acute respiratory syndrome (SARS) is a disease caused by SARS-CoV. The main symptoms of SARS include fever, cough, headache, muscle pain, and other symptoms of respiratory infection. Most SARS patients recover with or without medical treatment. Its fatality rate is about 10%; those over 40 years of age or with underlying diseases (such as coronary heart disease, diabetes, asthma, and chronic lung diseases) are most at risk to develop the fatal disease.

What is Middle East Respiratory Syndrome (MERS)?

Middle East Respiratory Syndrome is caused by MERS-CoV. It was first reported in middle-eastern countries including Saudi Arabia, United Arab Emirates etc. People who are infected by MERS-CoV can develop acute respiratory distress syndrome (ARDS), while the most common manifestations being fever with tremors, coughing, shortness of breath, sore muscles and gastrointestinal symptoms such as diarrhea, nausea, vomiting or stomachache.

Severe cases are featured by respiratory failure which require mechanical ventilation and supportive treatment in ICU. Some patients developed organ failures, especially renal failure and sceptic shock which eventually led to death. The case fatality rate is about 40%. Since the onset of the first MERS case in September 2012 until May 2015, MERS cases have been reported in 25 countries around the world, posing a serious threat to public health.

What is novel coronavirus? Why has it become epidemic?

The newly discovered coronavirus is a mutated novel coronavirus (β genus), which is named 2019-nCoV by the WHO and SARS-CoV-2 by the ICTV. On January 10, 2020, genomic sequencing of the first sample of 2019-nCoV was completed, and the viral genomic sequences of five more samples were subsequently announced.

Due to the antigenic mutations that made this corona virus new to humans, the general population lacks immunity against the new strain. Furthermore, there are more than one routes of transmission for this virus. These factors resulted in the novel coronavirus becoming epidemic.

What is community-acquired pneumonia?

Community-acquired pneumonia (CAP) refers to infectious pulmonary parenchymal pneumonia (including in the alveolar wall, which belongs to the lung interstitium in a broad sense) contracted outside the hospital setting, including pneumonia from known pathogens presenting after admission within its average incubation period.

What are the diagnostic criteria for community-acquired pneumonia?

The diagnostic criteria for community-acquired pneumonia are:

1. Onset in community.
2. The clinical manifestations of pneumonia are as follows.

• New presentation of cough, sputum, or exacerbation of existing respiratory diseases, with or without purulent sputum/chest pain/dyspnea/hemoptysis.
• Fever.
• Pulmonary consolidation and/or presence of wet rales.
• WBC (white blood cells) counts higher than 10×109/L or lower than 4 × 109/L, with or without a left shift of neutrophil nucleus (a sign of immature neutrophils).

3. Imaging characteristics. Radiographic examination revealing patchy infiltrates, lobular/segmental consolidation, or interstitial changes with or without pleural effusion.

If any items in (2) is positive and the imaging results support, a diagnosis of community-acquired pneumonia could be made after ruling out non-infectious diseases.

Which pathogens cause community-acquired pneumonia?

The most common pathogens that cause acute respiratory diseases include bacteria, viruses, or a combination of bacteria and virus. New pathogens, such as the novel coronavirus, can cause an epidemic or pandemic of an acute respiratory disease.

Bacteria are the main cause of community-acquired pneumonia. Streptococcus pneumonia is one of the most common bacterial pneumonia. Other bacterial pathogens include Mycoplasma, Chlamydia, Klebsiella pneumoniae, Escherichia coli, and Staphylococcus aureus; pneumonia caused by Pseudomonas aeruginosa and Acinetobacter baumannii have also been reported.

The virus detection rate for adult CAP patients in China is 15% to 34.9%, with influenza viruses including Haemophilus influenzae occupying the top spot. Other viral pathogens include parainfluenza virus, rhinovirus, adenovirus, human metapneumovirus, respiratory syncytial virus, and coronavirus. 5.8% to 65.7% of patients with positive virus test results are coinfected with bacteria or atypical pathogens.

How is community-acquired pneumonia transmitted?

Theoretically, all pathogens that cause community-acquired pneumonia have potential for human-to-human transmission. Routes of transmission from the source of infection to susceptible populations are droplet transmission, contact transmission, and airborne transmission.

Apart from the cold weather, the major factors such as movement of population (for example, the sizable migration during Spring Festival in China) makes winter more likely for respiratory infectious diseases to strike. It is mainly transmitted through droplets emitted by the patients or virus carriers when they cough or sneeze.

What are the risk factors for transmission of community-acquired pneumonia?

Autumn and winter are seasons prone to see the prevalence of respiratory viruses such as influenza, and various other respiratory infections may occur. This made it difficult to distinguish the early stage of COVID-19 from other upper respiratory infections.

The main sources of infection in community-acquired pneumonia include patients, their families, visitors, and their living environment.

The dissemination and outcomes of community-acquired pneumonia are associated with the following factors.

1. Environmental conditions: air pollutants, overcrowding in confined spaces, humidity, indoor hygiene, seasons, and temperature.
2. Accessibility and effectiveness of health care services and infection prevention measures: Accessibility and availability of vaccines and health care facilities, and isolation capabilities.
3. Host factors: age, smoking habits, transmissibility, immune status, nutritional status, previous infection or co-infection of other pathogens, and overall health.
4. Pathogen characteristics: routes of transmission, infectivity, virulence, and microbial population (inoculation size).

How to prevent community-acquired pneumonia?

Control the source of infection: When coughing or sneezing, the patient with acute respiratory diseases should cover their nose and mouth with the arm or other materials (handkerchiefs, paper towels, or masks) to reduce droplet transmission. After exposure to respiratory secretions, perform hand hygiene immediately, and wash hands frequently in daily life.

Personal precautions are as follows:

1. Maintain a balanced diet, ensuring adequate nutrition, and maintaining oral health can help prevent against infection.
2. Exercise regularly to boost immunity.
3. Quit smoking, limit alcohol consumption, and stay in good spirits.
4. Ensure indoor ventilation: natural ventilation and/or use of exhaust fans for better airflow.
5. Get vaccinated if available.

Who are susceptible to 2019-nCoV?

“The novel coronavirus is newly emergent in humans. Therefore, the general population is susceptible because they lack immunity against it. 2019-nCoV can infect individuals with normal or compromised immunity. The amount of exposure to the virus also determines whether you get infected or not. If you are exposed to a large amount of virus, you may get sick even if your immune function is normal. For people with poor immune function, such as the elderly, pregnant women or people with liver or kidney dysfunction, the disease progresses relatively quickly and the symptoms are more severe.

The dominant factor determining whether one gets infected or not is the chance of exposure. So, it cannot be simply concluded that better immunity will lower one’s risk of being infected. Children have fewer chances of exposure and thus a lower probability of infection. However, at the same exposure, senior people, people with chronic diseases or compromised immunity are more likely to get infected.

What are the epidemiological characteristics of COVID-19?

The emergent epidemic of COVID-19 has experienced three stages: local outbreak, community communication, and widespread stage (epidemic).

Transmission dynamics: in the early stage of the epidemic, the average incubation period was 5.2 days; the doubling time of the epidemic was 7.4 days, i.e., the number of people infected doubled every 7.4 days; the average continuous interval (the average interval time of transmission from one person to another) was 7.5 days; the basic regeneration index (R0) was estimated to be 2.2-3.8, meaning that each patient infects 2.2-3.8 people on average.

Main average intervals: for mild cases, the average interval from onset to the initial hospital visit was 5.8 days, and that from onset to hospitalization 12.5 days; for severe cases, the average interval from onset to hospitalization was 7 days and that from onset to diagnosis 8 days; for fatality cases, the average interval from onset to diagnosis was significantly longer (9 days), and that from onset to death was 9.5 days.

Communication stages: The COVID-19 epidemic passed three stages: 1) the stage of local outbreak (cases of this stage are mostly related to the exposure of a seafood market); 2) the stage of community commu“nication (interpersonal communication and clustering transmission in communities and families); 3) widespread stage (rapid spread, with large population flow, to the entire country of China and even the world.)

What are the routes of transmission of SARS-CoV-2?

COVID-19 spreads through multiple routes. Understanding these transmission pathways is essential for effective prevention.

1. Airborne/Aerosol transmission: This is now recognized as a primary route of transmission. When infected people breathe, talk, sing, cough, or sneeze, they release respiratory particles of various sizes containing the virus. Smaller aerosol particles (less than 5 μm) can remain suspended in the air for minutes to hours and travel beyond 6 feet, especially in poorly ventilated indoor spaces. This is why ventilation and air filtration are critical prevention measures.
2. Respiratory droplets transmission: Larger droplets (greater than 5 μm) are expelled when coughing, sneezing, or talking. These typically fall to the ground within 6 feet and are a significant transmission route during close contact.
3. Contact transmission: The virus can be transmitted through direct contact with an infected person or indirect contact with contaminated surfaces (fomites). However, surface transmission is now considered a less common route than initially thought. The virus from contaminated hands can enter through the mucous membranes of the mouth, nose, and eyes.
4. Fecal-oral transmission: The virus has been detected in feces of infected patients, suggesting possible fecal-oral transmission, though this is not considered a major route.
5. Vertical transmission: Mother-to-child transmission can occur during pregnancy, delivery, or through close contact after birth, though it appears to be relatively uncommon.

Key Prevention Insight: Since airborne transmission is significant, especially indoors, improving ventilation, using air filtration (HEPA filters), wearing well-fitted masks, and avoiding crowded indoor spaces are important prevention strategies.

What is droplet transmission?

A droplet generally refers to a water-containing particle with a diameter greater than 5 μm.

Droplets can enter mucosal surfaces within a certain distance (typically 1 m). Due to the relatively large size and weight of the droplets, they cannot stay suspended in the air for too long.

Generation of respiratory droplets:

1. Coughing, sneezing or talking.
2. During invasive respiratory tract procedures, such as suctioning or bronchoscopy, tracheal intubation, cough-stimulating movements including changing positions in bed or patting backs, and cardiopulmonary resuscitation, etc.
3. Pathogens transmitted by droplets: influenza virus, SARS coronavirus, adenovirus, rhinovirus, mycoplasma, group A streptococcus and meningococcus (Neisseria), and recently discovered 2019-nCoV.

What is airborne transmission?

Airborne transmission is also known as aerosol transmission. Aerosols are suspensions of tiny particles or droplets that can be transmitted through the air. They are generally considered to be less than 5 μm in diameter, and the pathogens carried by them can still be infectious after traveling long distances. Airborne pathogens can also be transmitted through direct contact. The airborne pathogens are classified as follows.

1. Through the airborne route only: Mycobacterium tuberculosis, Aspergillus.
2. Through multiple routes, but mainly airborne: measles virus, varicella-zoster virus.
3. Usually through other routes, but can also be transmitted through airborne only in special scenarios (like tracheal intubation/incision, open-airway suctioning and other aerosol-generating procedures): smallpox virus, SARS coronavirus, 2019-nCoV, Influenza virus and norovirus etc.

What is contact transmission?

Contact transmission refers to the transmission of pathogens through direct or indirect contact through fomites (pathogen-carrying objects).

1. Direct contact. Pathogens are transmitted through direct mucosal or skin contact with an infected host.
   • Blood or bloody fluids enter the body through mucous membranes or non-intact skins (mainly viruses).
   • Transmission caused by contact with secretions containing certain pathogens, commonly for infections by bacteria, viruses, parasites etc.
2. Indirect contact. Pathogens are transmitted through contaminated objects or people. Pathogens of intestinal infectious diseases are mostly transmitted through indirect contact.
3. Other important pathogens transmitted through indirect contact: MRSA (benzoxazole/methicillin-resistant Staphylococcus aureus), VRE (vancomycin-resistant enterococcus), Clostridium difficile.

What is a close contact?

Close contacts refer to persons who have contact with a patient who is confirmed or suspected with infection of 2019-nCoV), including the following situations.

1. Those who live, study, work or have other forms of a close contact with a patient.
2. Medical personnel, family members or others who have had a close contact with a patient without taking effective protective measures during diagnosing, treatment, nursing and visiting.
3. Other patients and their accompanying people sharing the same ward with an infected patient.
4. Those who shared the same transportation or elevator with the patient.
5. Those who are deemed as such through on-the-spot investigations.

Why should close contacts be put under isolated medical observation, and for how long?

Monitoring close contacts is essential for preventing further transmission. The observation period is based on the virus's incubation period—the time between exposure and symptom onset.

Current Guidelines (as of 2023-2024): Isolation and quarantine recommendations have evolved as our understanding of COVID-19 has improved:

• Isolation (for infected individuals): The CDC recommends isolating for at least 5 days after symptom onset or positive test. You may end isolation after day 5 if you are fever-free for 24 hours without medication and symptoms are improving, but should wear a mask around others through day 10.
• Quarantine (for exposed individuals): Recommendations vary based on vaccination status and prior infection. Generally, monitoring for symptoms for 10 days after exposure is advised. Testing 5 days after exposure is recommended.

Note: Guidelines vary by country and may change based on local conditions and emerging variants. Always consult your local health authority for the most current recommendations.

What are the clinical manifestations of COVID-19?

The onset of COVID-19 is mainly manifested as fever, but some early patients may not have fever, with only chills and respiratory symptoms, which can occur together with mild dry cough, fatigue, poor breathing, diarrhea etc. However, runny nose, sputum and other symptoms are rare. Patients may gradually develop dyspnea. In severe cases, the disease can progress rapidly, causing acute respiratory distress syndrome, septic shock, irreversible metabolic acidosis, and coagulation disorders in just a matter of days. Some patients start out with mild symptoms without fever. The majority of patients have a good prognosis, while a few become critically and sometimes fatally ill.

Do you know something on laboratory testing for COVID-19?

2019-nCoV can be identified by real-time reverse transcription polymerase chain reaction (rRT-PCR). For each case, specimens to be tested should be from lower respiratory tracts, such as bronchial/alveolar lavage fluid and deep sputum. Also, serum samples should be collected both at the onset of symptoms and after 14 days.

In the early stages of the disease, the white blood cell count stays normal or lower, but the lymphocyte count is decreased. While some patients have elevated liver enzymes, muscle enzymes, and myoglobin, most patients have elevated C-reactive protein and erythrocyte sedimentation rate. The procalcitonin levels stay normal and D-dimer is elevated in severe cases.

What are the characteristics of COVID-19 chest films?

In the early stages, chest films feature multiple small patchy shadows and interstitial changes, especially in the peripheral third of the chest, which then progress to bilateral ground glass opacities and pulmonary infiltrates. In severe cases, pulmonary consolidations and even “white-out” of the lungs are seen. Pleural effusions are rare.

How to identify COVID-19 cases clinically?

Persons who meet both the following conditions are considered suspected cases.

1. Epidemiological history. The case has a travel or residence history in the epidemic areas within two weeks of the onset, or had a contact(s) with patients from the epidemic areas within 14 days of the onset, or other patients with fever and respiratory symptoms in the communities with reported cases or clustered outbreak.
2. Clinical features. The most common symptom is fever. Some patients may not present with fever, but only chills and respiratory symptoms. Chest films show characteristics of viral pneumonia. During the early stage of the disease, white blood cell count is normal or below normal, while lymphocyte count may decrease.

How to confirm COVID-19 cases?

Once a case is identified as a suspected case, a positive result for 2019-nCoV nucleic acid on rRT-PCR testing of specimens (sputum, throat swabs, lower respiratory tract secretions etc.) or highly homologous sequences to the known novel coronavirus found after gene sequencing of the virus from a patient can confirm the diagnosis.

How to diagnose severe COVID-19 cases?

Severe cases refer to patients with unstable vital signs and rapid disease progression, with dysfunction or even failures of more than two organ systems. The progression of the disease may endanger the lives of patients.

What is the difference between COVID-19 and other pneumonia?

1. Bacterial pneumonia. Common symptoms include coughing, coughing up sputum, or exacerbation of the original respiratory symptoms, with purulent or bloody sputum, with or without chest pain. It is generally not considered a contagious disease.
2. SARS/MERS. Although the novel coronavirus is in the same family as SARS and MERS coronaviruses, a genetic evolution analysis shows that it belongs to a different branch of the same subgroup. It is neither a SARS nor a MERS virus, based on the viral genomic sequences. Due to the similarities between COVID-19-and SARS/MERS-caused pneumonia, it is challenging to distinguish them with clinical manifestations and imaging results. Therefore, a pathogen identification test by rRT-PCR is needed.
3. Other viral pneumonia. Pneumonia caused by influenza virus, rhinovirus, adenovirus, human metapneumovirus, respiratory syncytial virus and other coronaviruses.

What should close contacts do with notice from Center of Disease Control?

Please follow the self-monitoring instructions and stay at home. Don’t panic. Don’t go to work. Don’t go out too often. Perform daily checks of health condition and report the records to the authority, and follow up with your community doctors regularly. If fever, cough or other symptoms appear, please go to community health centers for further evaluation and treatment.

What should I do if I am possibly infected with COVID-19?

Promptly go to the local designated medical institution for evaluation, diagnosis and treatment. When a seeking medical attention for a possible infection of 2019-nCoV, you should inform your doctor about your recent travel and residence history, especially if you’ve been to the epidemic areas recently, and any history of contact with pneumonia patients or suspected 2019-nCoV cases, and animals. It is extra important to note that surgical masks should be worn throughout the visit to protect yourself and others.

How to choose a medical institution for treatment?

Isolation and treatment should be performed in a hospital with proper conditions for isolation and protection. Critical cases should be admitted to an ICU as soon as possible.

What should be done if a patient requires transportation?

Patients should be transported in designated vehicles that are regularly disinfected and manned with well protected personnel.

Are there any drugs or vaccines against COVID-19?

Vaccines: Multiple safe and effective COVID-19 vaccines have been developed and authorized worldwide since late 2020. The main vaccine types include:

• mRNA vaccines (Pfizer-BioNTech, Moderna) – These vaccines use messenger RNA to instruct cells to produce a harmless spike protein, triggering an immune response.
• Viral vector vaccines (Johnson & Johnson, AstraZeneca) – These use a modified harmless virus to deliver genetic instructions for the spike protein.
• Protein subunit vaccines (Novavax) – These contain purified spike proteins to trigger immunity.
• Inactivated virus vaccines (Sinovac, Sinopharm) – These use killed virus particles to generate immune response.

Booster doses are recommended to maintain protection, especially as new variants emerge. Consult your local health authority for current vaccination recommendations.

Treatments: Several antiviral treatments are now available for COVID-19:

• Paxlovid (nirmatrelvir/ritonavir) – An oral antiviral that reduces the risk of severe illness when taken early after symptom onset.
• Remdesivir – An intravenous antiviral approved for hospitalized patients and high-risk outpatients.
• Molnupiravir – An oral antiviral option for adults at high risk of severe disease.
• Monoclonal antibodies – While effectiveness varies with different variants, these may be used in certain cases.

Treatment should be initiated as early as possible after diagnosis, ideally within 5 days of symptom onset. Consult a healthcare provider for appropriate treatment options based on your individual circumstances and current guidelines.

How to treat COVID-19?

1. Put patients to bed rest, provide with supportive care, maintain good hydration and electrolyte balance, internal homeostatis, and closely monitor vital signs and oxygen saturation.
2. Monitor routine blood and urine test results, C-reactive protein (CRP), biochemical indicators (liver enzyme, myocardial enzyme, renal function, etc.), and coagulation function accordingly. Perform an arterial blood gas analysis when needed, and regularly review chest X-ray images.
3. According to the changes in oxygen saturation, provide a timely effective oxygen therapy, including nasal catheter, oxygen mask, transnasal high-flow oxygen therapy, and noninvasive or invasive mechanical ventilation, etc.
4. Antiviral therapy: There are currently no antiviral drugs with good efficacy.
5. Apply antibacterial drug treatment: strengthen bacteriological monitoring, and start antibacterial treatment when there is evidence of secondary bacterial infection.
6. Traditional Chinese medicine treatment. Treat according to the syndrome.

What are the clinical criteria for quarantine release and discharge?

1. The condition of the patient is stable and fever has subsided.
2. Lung imaging shows a significant improvement with no sign of organ dysfunction.
3. The patient has had stable breathing, clear consciousness, unimpaired speech, normal diet and body temperature for more than 3 days. Respiratory symptoms have improved significantly, and two consecutive tests for respiratory pathogenic nucleic acid have been negative (at least one day in-between tests).

How to prevent respiratory infections in spring and winter?

Wash hands frequently with plain or antimicrobial soap and rinse with running water. Be sure to dry hands with clean towels. Wash hands immediately after contact with respiratory secretions (for example after sneezing).

Practice good respiratory hygiene/cough practices. Cover mouth and nose while coughing/sneezing with tissue, towel etc. and avoid touching eyes, nose or mouth afterwards before thoroughly washing hands.

Strengthen overall health and immunity. Keep a balanced diet, get enough sleep and regular exercise, and also avoid overworking.

Maintain good hygiene and proper ventilation. Open windows regularly throughout the day to let in fresh air.

Avoid crowded places or contact with persons with respiratory infections.

Seek a medical attention if fever, cough, sneezing, runny nose or other respiratory symptoms appear.

Why does flu caused by viruses become pandemic?

Influenza is mainly transmitted through respiratory droplets and contact from infected to susceptible people, or through contact with contaminated items. In general, its incidence peaks in autumn and winter. Human influenza is mainly caused by influenza A virus and influenza B virus. Influenza A viruses often undergo antigen mutations and can be further classified into subtypes such as H1N1, H3N2, H5N1, and H7N9. When new influenza virus subtypes appear, they easily become a pandemic because the population generally lacks immunity against them.

How to keep yourself away from the novel coronavirus?

1. 2019-nCoV is mainly transmitted by droplets and contacts, therefore medical surgical masks must be worn properly.
2. When sneezing or coughing, do not cover nose and mouth with bare hands but use a tissue or a mask instead.
3. Wash hands properly and frequently. Even if there are viruses present on hands, washing hands can block the viruses from entering respiratory tract through nose or mouth.
4. Boost your immunity, and avoid going to crowded and enclosed places. Exercise more and have a regular sleep schedule. Boosting your immunity is the most important way to avoid being infected.
5. Be sure to wear the mask always! Just in case you come in contact with an infected person, wearing a mask can prevent you from inhaling virus-carrying droplets directly.

Can a mask block such small coronaviruses?

The masks are effective. Because the purpose of wearing the mask is to block the ‘carrier’ by which the virus is transmitted, rather than directly blocking the viruses. Common routes for transmission of respiratory viruses include close contact over a short distance and aerosol transmission over a long distance. Aerosols which people usually come in contact with refer to respiratory droplets from patients. Wearing a mask properly can effectively block respiratory droplets and therefore prevent the virus from directly entering the body.

Please be reminded that it is not necessary to wear a KN95 or N95 respirator. Regular surgical masks can block most virus carrying droplets from entering the respiratory tract.

What are the features of masks for different purposes?

Major types of masks: N95/KN95 respirators, surgical face masks, and cotton face masks.

N95/KN95 respirators can filter 95% of particles with an aerodynamic diameter greater than or equal to 0.3 μm, and block viruses. They can help prevent airborne diseases.

Disposable surgical face masks have 3 layers. The outer layer is hydrophobic non-woven layer which prevents droplets from entering the mask; the middle layer has a filter to block 90% of particles with a diameter greater than 5μm; and the inner layer in contact with the nose and mouth absorbs moisture. They are typically for sterile medical operations and be used to prevent airborne diseases.

Cotton face masks are heavy, stuffy, and do not fit closely to the face, and thus not effective against viruses.

Any difference between KN95 respirator and N95 respirator?

Respirators are a kind of respiratory protective gear. It’s designed to more closely fit on the face than regular masks, and effectively filter particles in the air. “N” indicates “non-oil-based uses” and a N95 mask can be used to protect against non-oil-based suspended particles; “95” means that the filtration efficiency is no less than 95%, indicating that this respirator, as proved by careful testing, can block at least 95% of very small (0.3 μm in size) tested particles.

If worn correctly, N95’s filtration efficiency is superior to regular and surgical masks. However, even if you wear it as required, it does not 100% eliminate the risks of infection.

KN95 is one of the ratings specified in the Chinese standard (GB 2626—2006) while N95 is one of the ratings specified in the American standard (42 CFR 84). The technical requirements and testing methods of these two ratings are basically the same, and they both have a filtration efficiency of 95% by their respective standards.

How to choose a mask?

The capability of masks to protect a wearer is ranked as follows: N95 respirators > surgical face masks > general medical masks > cotton masks.

N95 respirators come in two types, with or without breathing valves. While N95 respirators may make breathing more difficult for people with chronic respiratory diseases, heart disease, or other diseases with breathing difficulty, N95 respirators with breathing valves can make breathing easier and help reduce heat build-up.

N95 respirators with or without breathing valves have the same protection capability for the wearer. However, N95 respirators with breathing valves cannot protect people nearby an infected wearer. Therefore, carriers of the virus should wear N95 respirators without breathing valves to prevent spreading the virus. To keep the sterility of an environment, N95 respirators with breathing valves are not suggested because the wearer may exhale bacteria or viruses.

How to put on, use and take off a mask?

1. After identifying the front, back, top, and bottom of the mask, wash your hands before wearing it. Make sure that the mask covers your nose and mouth, fits closely around the face to form a closed environment, so air passes through the mask, but not the gaps around it. Then, place the ear loops around each the ears.
2. Besides the front and back side, the surgical mask also has a stiff bendable strip on top. When wearing it, with the front side facing outwards, you also need to make sure the stiff bendable strip is on top, molded around the nose.
3. Wash hands thoroughly before taking off your mask. Push the front side of mask with one hand while holding the ear loops and remove them from around each ear with the other. Fold the mask with the back side in. If the back side is not contaminated, a limited reuse is allowed.

How often should a mask be replaced? Can N95 respirators be extendedly used or reused?

All masks have a limited protective effect and need to be replaced regularly in the following cases:

• when it is difficult to breath though the mask;
• when the mask is damaged;
• when the mask cannot fit snugly to the contour of the face;
• when the mask is contaminated with blood or respiratory droplets etc.;
• after contact with, or exit from, an isolation ward of any patient infected with an infectious disease requiring contact precautions (the mask has been contaminated).

At present, international organizations including the World Health Organization, have no definitive guidelines as to the optimal wearing time of N95 respirators. China has not yet introduced the relevant guidelines regarding the time of use of masks, either. Researches on the protective capability and wearing time of N95 respirators show that the filtration capability stays at 95% or above after 2 days of use, while the respiratory impedance has not changed much; the filtration capability is reduced to 94.7% after 3 days of use. The U.S. Centers for Disease Control and Prevention recommends that when N95 respirators are in short supply, N95 respirators can be extendedly used or reused unless they are visibly dirty or damaged (such as creased or torn).

How to keep my glasses from fogging up with a mask on?

To prevent glasses from fogging up while wearing a mask, please wash your hands before touching the mask, make sure the mask is worn in a correct orientation, make sure it fits your face snugly to form a closed environment allowing air to pass through the mask instead of the gaps around it.

How should special populations choose a mask?

• Pregnant women should choose masks they find comfortable for them. It is suggested that pregnant women consult with doctors for professional instructions on wearing masks.
• The elderly and patients with chronic diseases should ask for professional instructions on wearing masks because the body conditions of these people vary. For example, patients with heart and lung diseases may feel uncomfortable when wearing a mask, and it may even aggravate their illnesses.
• Generally, children’s face is small, so it is recommended that children wear masks specially made for the underaged by reputable manufacturers.

Why is handwashing important in preventing respiratory diseases?

The hands are the key medium in transmission of viruses that are transmitted through water, food, blood or blood products, respiratory droplets, digestive tract, in addition to direct or indirect touching. Studies show that proper handwashing is one of the most effective measures to prevent diarrhea and respiratory infections.

How to wash hands correctly?

Step 1: Apply soap to hands and scrub palm to palm with fingers interlaced.

Step 2: Put one palm on the back of another hand and scrub your fingers. Change hands.

Step 3: Scrub between your fingers.

Step 4: Rub the back of your fingers against your palms. Do the same with the other hand.

Step 5: Scrub your thumb using the other hand. Do the same with the other thumb.

Step 6: Rub the tips of your fingers on the palm of the other hand.

Step 7: Rub the wrist of one hand with the other hand while rotating it. Do the same with the other hand.

In each of the above steps, do each step no fewer than 5 times, and finally rinse your hands under running water.

What are the key moments for hand hygiene in daily life?

1. When you cover a cough or a sneeze with your hand.
2. After caring for a patient.
3. Before, during, and after preparing food.
4. Before eating.
5. After going to the toilet.
6. After touching animals.
7. After touching elevator buttons and door handles or knobs.
8. After coming home from outside.

How to clean hands if clean water is not available?

You can clean your hands with an alcohol-based hand sanitizer. Coronaviruses are not resistant to acid or alkali but are sensitive to organic solvents and disinfectants. 75% alcohol can inactivate the virus, so alcohol-containing disinfection products of an absolute (100%) concentration can be used as an alternative to washing hands with soap and running water.

Does handwashing with soap and clean water work against coronaviruses?

Yes, it does. Frequent hand washing is one of the effective measures to prevent viral infection such as rhinovirus and coronavirus. Rubbing hands with soap and water can effectively remove dirt and microorganisms on the skin, and rinsing out the soap under running water can also relieve irritation to the skin. Therefore, authoritative organizations such as the Chinese Center for Disease Control and Prevention, the World Health Organization, and the United States Centers for Disease Control and Prevention all recommend washing hands thoroughly with soap and running water.

Can 75% alcohol reduce risk of 2019-nCoV infection?

Yes. Coronaviruses are sensitive to organic solvents and disinfectants. 75% alcohol, chloroform, formaldehyde, chlorine-containing disinfectants, peracetic acid, and ultraviolet rays can inactivate the virus, so wiping hands and mobile phones with alcohol can prevent COVID-19 infection.

How to take care of the COVID-19 patient at home?

1. Quarantine the patient from the rest of the family members and maintain a distance of at least one meter.
2. Wear a mask when looking after the patient. Discard the mask after each use.
3. Wash hands thoroughly with soap after having contact with the patient. The patient’s living space should be well ventilated.

Is it necessary for suspected cases with mild symptoms to be quarantined at home?

Yes. In case of insufficient treatment capacity and medical resources, The World Health Organization recommends that patients with mild symptoms (low-grade fever, coughing, sneezing, and asymptomatic sore throat) and no chronic diseases (such as lung diseases, heart diseases, kidney failure, or immune diseases) could be quarantined at home.

Notes:

1. During the quarantine at home, patient needs to keep in touch with medical professionals until a full recovery.
2. Medical professionals must monitor the development of symptoms to assess the patient’s condition.
3. Patients and family members should maintain good hygiene and receive health care, prevention instructions and monitoring.
   Caution! Deciding whether a patient is to receive home quarantine requires careful clinical assessment of safety and health risks involved in home healthcare.

How to home quarantine for suspected infections?

1. Arrange a well-ventilated single room for the patient.
2. Limit the number of caretakers. It is better to designate one person who is in good health and has no chronic diseases to take care of the patient. All visits should be avoided.
3. Family members of the patient should live in different rooms or at least keep more than one meter from the patient. Nursing mothers can continue to breastfeed their babies.
4. Restrict the movement of the patient and minimize the shared areas between the patient and family members. Make sure that the shared areas (kitchen, bathroom, etc.) are well-ventilated by opening windows frequently.
5. Wear a mask when staying in the same room with the patient. The mask should fit the face snugly. Avoid touching or adjusting the mask with unclean hands. Replace the mask immediately when it is contaminated. Wash hands after removing the mask.
6. Wash hands after having any direct contact with the patient, or entering or exiting the patient’s isolation ward. Wash hands before and after preparing food, before eating, after going to the toilet, and when hands look dirty. If hands are not visibly dirty, clean them with a hand sanitizer; if hands are visibly dirty, wash them with soap and water.
7. After washing hands with soap and water, it is best to use disposable paper towels to dry hands. If they are not available, wipe them with a clean and dry textile towel, and replace it when it becomes wet.
8. Maintain good hygiene of the respiratory tract (wear masks, use tissues or lift your elbow to cover your mouth when coughing or sneezing, and wash hands immediately after coughing and sneezing).
9. Disinfect and discard the items used to cover the nose and mouth, or wash them properly after use (such as washing handkerchiefs with soap or detergent and water).
10. Avoid direct contact with human droplets, especially oral or respiratory secretions, and avoid direct contact with patient’s stool.
11. Wear single-use gloves when cleaning the mouth and respiratory tract of patients as well as handling the patient’s feces and urine. Do not discard the gloves carelessly.
12. Avoid direct contact with the patient or items contaminated by the patient, such as toothbrushes, tableware, food, drinks, towels, bath towels, bed sheets, etc. Wash dishes with detergent or discard them after use.
13. Use ordinary household disinfectants containing diluted bleach (bleach: water = 1: 99) (most household bleaches contain 5% sodium hypochlorite) to regularly clean and disinfect the frequently-touched objects, such as bedside tables, bed frame and another bedroom furniture. Clean and disinfect bathroom and toilet surfaces at least once a day.
14. Use ordinary laundry detergent and water to wash the patient’s clothing, bed sheets, bath towels, towels, etc., or wash them in a washing machine at 140-194ºF with ordinary household laundry detergent, and then dry the above items completely. Put contaminated bedding in laundry bags. Do not shake contaminated clothing to avoid direct contact with skin and your clothes.
15. Wear disposable gloves and protective clothing (such as a plastic apron) before cleaning and touching clothing, bedding and surfaces of objects contaminated by human secretions. Wash hands before putting on gloves and after removing them.
16. Patients should stay at home until a full recovery. Deciding whether the patient has recovered requires clinical and/or laboratory diagnosis (rRT-PCR assays should be carried out at least two times and produce negative results; the interval between two consecutive assays should be at least 24 hours).

What should I do amid a close contact with a COVID-19 patient?

Monitoring close contacts: All persons (including medical professionals) who may have been in contact with a suspected case should have a 14-day medical observation. The observation starts from the last day of contact with the patient. Seek medical help as soon as you experience any symptoms, especially fever, respiratory symptoms such as coughing, shortness of breath, or diarrhea. During the observation, contacts should keep in touch with medical professionals. Medical professionals should inform the contacts in advance, if symptoms present, where they can seek medical help, the most suggested transportation, when and where to enter a designated hospital, and what infection control measures to take.

Specific instructions are as follows:

1. Notify the hospital in advance and inform them that a contact with symptoms is going to the hospital.
2. Wear a surgical mask on the way to the hospital.
3. Avoid taking public transportation to the hospital. Call an ambulance or use a private vehicle, and try to keep the windows open on the road.
4. Close contacts of patients should maintain respiratory hygiene at all time and wash their hands frequently. Stay far away from other people (> 1 m) while standing or sitting on the road to or at the hospital.
5. Contacts of patients and their caregivers should wash their hands properly.
6. Any surfaces contaminated with respiratory secretions or bodily fluids on the way to the hospital should be cleaned and disinfected with ordinary household disinfectants containing diluted bleach.

How to control hospital infection?

The medical workers must strictly follow hygiene and infection control standards in healthcare facilities and the medical procedure protocols to reduce the transmission risks. They must take a better control of hospital infection by practicing good personal protection measures, hand hygiene, ward management, environmental disinfection and waste management. Pre-examination and triage office/station: wear protective work clothes, work caps, medical surgical masks, etc. Outpatient, emergency, fever outpatient and isolation ward: during daily consultations and rounds, wear protective work clothes, work caps, medical surgical masks, etc.; when contacting blood, body fluids, secretions or excreta, wear latex gloves; when performing operations/procedures that may incur aerosol or body fluid splashing such as tracheal intubation, airway care and sputum suction, wear N95 masks, facial screens, latex gloves, impermeable isolation clothing, protective clothing and respirator if necessary. The visitation control system should be strictly implemented for the patients in isolation. If it is necessary to visit a patient, the visiting personnel should be instructed for proper personal protection measures according to the relevant regulations.

Why do the medical staff of fever clinic wear protective clothing in consultations?

(1) Medical personnel are the main force of epidemic prevention and control. Only when they do well in personal protection can they help patients better.
(2) In order to ensure the health and occupational safety of medical workers so that they can detect and rescue suspected cases in time and effectively, the prevention and control measures and nosocomial infection control must be enhanced in all levels of hospitals, and the protection of medical workers should be strengthened by monitoring their health and providing care and support.

What personal protective equipment is required for healthcare institutions?

Medical institutions should be equipped with disposable working caps, disposable surgical face masks, goggles, work clothes (white gown), protective clothing, disposable latex gloves, disposable shoe covers and comprehensive respiratory protective devices or positive pressure headgears, etc.

What lifestyle is recommended amid the outbreak of COVID-19?

1. Eat high-protein foods daily including fish, meat, eggs, milk, legumes and nuts, keep an adequate intake based on daily diet. Do not eat wild animal meats.
2. Eat fresh fruits and vegetables every day, and increase the intake based on daily diet.
3. Drink no less than 1500 mL of water per day.
4. Have a varied, diverse diet of different types, colors and sources. Eat more than 20 kinds of food every day. Eat a balanced diet of animal- and plant-based foods.
5. Ensure enough intake of nutrition based on the regular diet.
6. Undernourished, elderly people and patients with chronic wasting diseases are recommended to supplement with commercial enteral nutrition solutions (foods for special medical purpose), and supplement no less than an extra 2100 kJ daily (500 kcal).
7. Do not fast or go on a diet during an epidemic of COVID-19.
8. Ensure regular rest and a minimum of 7 hours of sleep each day.
9. Start a personal exercise regimen with no less than 1 hour of exercise per day. Do not participate in group exercises.
10. During an epidemic of COVID-19, it is recommended to supplement with multi-vitamins, minerals, and deep-sea fish oil.

How to exercise amid outbreak of COVID-19?

Follow a comprehensive exercise program, increase the intensity progressively, and exercise consistently.

1. Follow comprehensive exercise programs, exercising every part and system of the body, and expanding the scope and types of your exercise to ensure different attributes of your physical fitness are enhanced.
2. Increase the intensity progressively. Start exercises from low intensity and gradually scale it up after your body has adapted to the initial intensity. It is suggested to do basic movements and learn easy techniques before moving onto higher level.
3. Exercise consistently. Keep exercising until it becomes a habit.

How do smoking and drinking affect your immune system?

Smoking causes an increase in nicotine concentration in blood, which could result in vasospasm and transient hypoxia in organs. Particularly, the decrease of oxygen in respiratory tract and viscera could damage immunity. Excessive drinking could harm the gastrointestinal tract, liver, and brain cells, and undermine immunity. It is recommended to quit smoking and limit alcohol intake.

How to prevent the infection by the novel coronavirus at home?

1. Raise health and hygiene awareness. Moderate exercises as well as enough and regular rest can boost immunity.
2. Maintain good personal hygiene. Cover your nose and mouth with a tissue when coughing or sneezing. Wash hands frequently and avoid touching your eyes, nose, or mouth with unwashed hands.
3. Maintain good hygiene in rooms, clean floor and furniture, separate household wastes and take out the rubbish timely.
4. Keep good ventilation. Ventilate every day to let fresh air in.
5. Disinfection. Apply disinfectant regularly to, and mop the floor and wipe the surface of furniture. The novel coronavirus is sensitive to ultraviolet rays and heat. Sustained heat at 132.8ºF for 30 minutes, 75% alcohol, chlorine-containing disinfectants, hydrogen peroxide disinfectants and chloroform can effectively inactivate the virus.
6. Avoid close contact with people who have symptoms of respiratory diseases (such as fever, cough, sneezing, etc.).
7. Avoid going to crowded and confined spaces. Wear a mask if you must go.
8. Do not eat wild animals. Avoid contact with poultry and wild animals, and do not handle fresh meat of wild animals.
9. Keep pets in strict captivity. Have your pets vaccinated. Maintain good hygiene for pets.
10. Follow the food safety precautions and habits. Eat thoroughly-cooked meat and hard-boiled eggs.
11. Pay attention to your body conditions. Seek medical help immediately in cases of symptoms such as fever, cough, etc.

How to ventilate my rooms?

The doors and windows of the home are closed most of the time in cold weather, so the air in rooms could be polluted quickly considering the confinement and indoor activities such as cooking. Therefore, windows should be opened from time to time to let fresh air in.

At present, there are no explicit international guidelines for proper ventilation. It is recommended to ventilate according to the environmental conditions indoors and outdoors. Ventilations in the morning, afternoon and evening are suggested when the air outside is good. The ventilation should be kept for 15 to 30 minutes. The frequency and time of ventilation should be decreased accordingly when the outdoor air is in poor quality.

How to prevent the infection by 2019-nCoV during travel?

1. Take a note of the weather at your destination, and bring enough clothes accordingly to keep warm.
2. Wear a mask while traveling by bus, train or plane, and drink enough water.
3. Maintain a regular rest schedule during the trip, eat balanced diets and exercise to maintain immunity.
4. Avoid a long stay in crowded places and wear masks.
5. Use disposable items to avoid cross infection when receiving guests or going to public places. For example, prepare disposable slippers when having guests at home; use disposable cups; bring your own towels when going to public bathrooms, etc.
6. Avoid contact with wild animals, stray cats and dogs.
7. Eat thoroughly-cooked meat because high temperatures can effectively kill viruses in food.
8. Seek medical help immediately if you have any symptoms of illnesses, and do not travel if you are sick.

Which commonly-used Chinese herbs can prevent COVID-19?

Based on the clinical characteristics of COVID-19, it can be classified as an "epidemic" or "pestilent" disease in traditional Chinese medicine. Its core pathogenic factors are "dampness, toxin, stasis and blockage." It mainly affects the lung and spleen, and may injure the collaterals and enter the blood. Drawing upon the clinical experiences of doctors currently treating COVID-19, both national and regional health administrative authorities have recommended specific TCM herbal formulas for treatments. The most commonly used TCM ingredients include: rhizoma phragmitis (lu gen), rhizoma imperatae (bai mao gen), radix angelicae dahuricae (bai zhi), rhizoma atractylodis macrocephalae (bai zhu), rhizoma atractylodis (cang zhu), honeysuckle (jin yin hua), herba pogostemonis (huo xiang), radix et rhizoma rhodiolae crenulatae (hong jing tian), rhizoma dryopteridis crassirhizomatis (guan zhong), rhizoma polygoni cuspidati (hu zhang), fructus tsaoko (cao guo), pericarpium citri reticulatae (chen pi), folium mori (sang ye), radix astragali praeparata (huang qi), radix ligustici brachylobi (fang feng), and herba eupatorii (pei lan). However, it is important to note that herbal formulas should only be used under the guidance of professionally-trained Chinese medicine physicians.

Also note that taking Isatis root (ban lan gen) or fumigating indoor spaces with burning vinegar are not effective means of preventing 2019-nCoV infection.

How to get mentally prepared during the outbreak of COVID-19?

1. Adjust your attitudes and view COVID-19 from a scientific perspective. During the early days of the outbreak, limited knowledge on the risks and prevention of COVID-19 might cause a sense of anxiety and panic among the public, which was exacerbated by rumors. Have confidence in the authoritative efforts for prevention and control and trust scientific research findings of the disease. Adjust your attitudes, act with caution and stay away from fear.
2. Acknowledge your anxiety and fear. Faced with an unknown epidemic, few people can stay calm. The increased number of confirmed cases would lead to the assumption that the new virus is present everywhere and is unpreventable, causing anxiety and fear. That is natural. Accept the status and avoid excessive self-blame for feeling such emotions.
3. Maintain a regular and healthy lifestyle: adequate sleep, a healthy balanced diet of diverse food groups, a regular work routine which may help distract ourselves from the epidemic, and a moderate exercise regimen.
4. Allow yourself to let off steam when you feel necessary. Occasional laughing, crying, shouting, exercising, singing, speaking, chatting, writing, or drawing can help release anger and anxiety, divert your attention, and calm down effectively. Watching TV or listening to music at home also helps to ease anxiety.
5. Relax and cope with your emotions. Relaxation techniques can help you release your negative emotions such as tension, depression, and anxiety. There are many ways of relaxation and the key to successful relaxation is to understand the basic principles of the techniques and practice.
   • Relaxation through visualization. Maintain a slow, steady and deep breath during the whole process, and feel warm energy flowing through your body with visualization.
   • Muscle relaxation. Relax your arms, head, trunk and legs successively. Keep the environment quiet, dim the light and minimize sensory stimuli. A simple five-step relaxation cycle consists of: focusing your attention → tensing your muscles → maintaining the tension → releasing the tension → relaxing your muscles.
   • Relaxation through deep breathing: this is the easiest way to relax that can be used in any situation where you feel nervous. Steps: stand up straight, put your shoulders down naturally, slightly close your eyes, and then inhale deeply and exhale slowly. It usually takes just a few minutes to feel relaxed.
6. Seek professional support. Seek counselling or medical treatment for unresolved tension, anxiety, fear, anger, sleep disorder, physical reactions, etc. On a different note, when a quarantined or suspected patient manifests extreme emotions and behaviors, prevention and control professionals should consider the possible onset of psychiatric disorders, and send the person in case to mental health institutions and personnel. Such extreme emotions and behaviors include: anxiety, depression, delusion, restlessness, uncontrollable and improper speech or actions, or even violent refusal or evasion of quarantine, and suicidal ideation.

How to prevent infection by 2019-nCoV at farmer's markets?

1. Avoid contact with livestock or wild animals without protective measures.
2. Avoid large crowds; wear a mask if contact is unavoidable.
3. Cough or sneeze into paper tissues, your sleeves or elbows while completely covering the nose and mouth. Seal used tissues in a plastic bag before discarding immediately in a closed bin labeled "residual waste" or "medical waste" to prevent the virus from spreading. After coughing or sneezing, wash hands with soap and water or an alcohol-based hand sanitizer.
4. Wash hands immediately after returning home. Fever and other symptoms of respiratory infections, especially persistent fever, indicate the need for an immediate hospital visit.

How to prevent infection by 2019-nCoV in cinemas and theaters?

During an epidemic outbreak, try to avoid visits to public spaces, especially places with large crowds and poor ventilation like cinemas. Wear a face mask if visits to public spaces are required. Cough or sneeze into tissues completely covering the nose and mouth. Seal used tissues in a plastic bag before discarding immediately in a closed bin labeled "residual waste" or "medical waste" to prevent the virus from spreading. Operators of public spaces should maintain a hygienic indoor environment, ensure regular ventilation and sterilization every day.

How to prevent infection by 2019-nCoV when traveling by public transportation?

Passengers on public transport such as bus, metro, ferry or airliners must wear face masks to reduce the risk of getting infected in crowded spaces. Seal used tissues in a plastic bag before discarding immediately in a closed bin labeled "residual waste" or "medical waste" to prevent the virus from spreading.

How to prevent infection by 2019-nCoV in the workplace?

Keep the workplace well-ventilated. Do not spit in public; you can spit into a tissue paper and then dispose of it in a closeable bin when convenient. Cough or sneeze into tissues while completely covering the nose and mouth. Seal used tissues in a plastic bag before discarding immediately in a closed bin labeled "residual waste" or "medical waste" to prevent the virus from spreading. Wash hands frequently to maintain personal hygiene; avoid all kinds of social gatherings during the epidemic.

How to prevent infection by 2019-nCoV in elevators?

During the 2003 SARS outbreak, an incidence of people becoming infected after taking elevators with cases has been reported.

An elevator carries a high risk of transmission due to its confined space. To prevent the spread of 2019-nCoV in elevators, the following measures should be taken:

1. The elevator should be thoroughly and regularly disinfected several times with ultraviolet irradiation, 75% alcohol or chlorine-containing disinfectants every day.
2. Minimize the risks of getting infected from sneezing by taking the elevators alone if possible.
3. Wear a mask before entering the elevator. If someone sneezes in the elevator while you have no masks on, cover your mouth and nose with your sleeves and measures like clothes changing and personal cleaning should be taken right after.

How to prevent infection by 2019-nCoV at wet markets?

1. Wash hands with soap and clean water after touching animals and animal products.
2. Disinfect equipment and work area at least once a day.
3. Wear protective suits, gloves and masks, when handling animals and fresh animal products.
4. Remove protective clothing after work, clean them daily and leave them in the work area.
5. Keep family members away from unwashed work clothes, shoes, etc.

How to prevent infection by 2019-nCoV in hospitals?

1. Wear a mask during hospital visits, especially visits to fever clinics or respiratory departments.
2. Avoid close contact with people presenting symptoms of respiratory diseases (such as fever, cough and sneezing).
3. Maintain good personal hygiene; cover nose and mouth with tissues when coughing or sneezing.
4. Wash hands with soap or alcohol-based hand sanitizer. Avoid touching eyes, nose, or mouth without washing hands.
5. Seal the used tissues in a plastic bag before discarding it in a closed bin of "other wastes" or medical wastes.

How to prevent infection by 2019-nCoV in colleges and universities?

1. Avoid gatherings;
2. Raise awareness. The departments for safety management should train staff, faculty, and students on proper prevention and personal protection.
3. Ensure rapid quarantine and notification of staff, faculty, and students with symptoms of fever, cough or other symptoms of respiratory infections. Discourage working or studying during sickness.
4. Ask students to provide details of the travel history and pay close attention to those who have returned from the regions, communities or families with the confirmed cases.
5. Screen students for symptoms of fever, cough and other symptoms of respiratory infections in the morning and afternoon.
6. Ensure an adequate supply of disposable masks, disinfectants, disposable gloves, and hand sanitizers.
7. The campus infirmary and departments for safety management should guide and supervise the cleaning, ventilation, and disinfection of classrooms, dormitories, canteens, libraries, and other public facilities.

How to prevent infection by 2019-nCoV in primary and secondary schools as well as nurseries?

1. Contingency plans and leadership accountability systems for the prevention and control of 2019-nCoV infection should be established, and responsibilities assigned to departments and individuals.
2. Campus medical staff and department for safety management should give lectures on the prevention and control of infection to staff, faculty and teachers for their understanding and awareness of the virus.
3. Campus medical staff and faculty should monitor students' health conditions, carry out morning and afternoon inspections, and check students for fever, cough and other symptoms of respiratory infections. Ensure rapid quarantine of students with symptoms and immediate notification of parents and local health departments.
4. Keep the campus dry and clean, rooms with adequate ventilation, disinfect public places and facilities daily, and equip hand wash sinks with hand sanitizers or soaps.
5. Reduce group activities. In classrooms, students should sit separately with adequate distance from each other. Arrange the meal times in canteens in successive, alternating batches.
6. Contact parents for student information on activities outside the school.

How can students avoid infection by 2019-nCoV at learning places?

1. Classrooms. Compared with other learning places, classrooms are more crowded. Therefore, keep the classroom clean and disinfect it daily. Ventilate the classroom 3 times every day, each time for 20-30 minutes. People inside should keep warm when ventilating the room. Maintain a proper social distance. Wear a mask, wash hands frequently, drink plenty of water, and avoid shouting or eating in the classroom.
2. Libraries. The library is an important public learning place for both teachers and students. The library staff should wear protective clothes and keep the library well-ventilated, dry, clean, and disinfected daily. Teachers and students should wash and disinfect their hands after borrowing books. They should wear a face mask and avoid rubbing their eyes, nose or mouth with their hands.
3. Laboratories. Laboratories are important public place at the school. Disposable latex gloves and masks should be worn when studying or doing experiments in a laboratory. After the experiment is completed, laboratory consumables should be properly disposed of while equipment and utensils should be sterilized promptly. The 7 steps of handwashing (See Question 54) should be followed.

How can students avoid infection by 2019-nCoV in their living space?

1. Canteens. Ensure food safety and hygiene, and strengthen inspection on meat products. Before starting work every day, canteen staff should take temperature, put on masks and wash hands. They should also replace masks regularly according to the guidelines. Areas for food processing and dining as well as tableware should be sterilized with ultraviolet light and high heat every day. Canteen toilets should be equipped with faucets, soap and disinfectants for handwashing. Reduce the number of large dining tables, arrange students and teachers to eat in batches, and maintain a proper distance between people in the queue to avoid over-crowding.
2. Stadiums. Teachers and students are advised to do moderate exercise, which is beneficial for health. High-intensity exercise or contact sports are not recommended, because the former can weaken people's immunity while the latter can potentially spread the virus.
3. Dormitories. Dormitories should be well-ventilated and clean. Regular disinfection should be carried out if possible. Students should wash hands after entering the dormitory from outside, and change and wash clothes and take shower regularly. Ensure regular and adequate sleep.

How to prevent infection by 2019-nCoV in elder-care settings?

1. Elder-care facilities should implement a closed-off management that restricts outdoor activities of residents, visits of their relatives and friends, and reception of new residents.
2. Take the travel history of the residents during the epidemic and immediately quarantine close contacts with confirmed patients.
3. The managing staff should know how to prevent and control the COVID-19 and take a 24-hour shift to respond to emergencies.
4. Ensure an adequate supply of personal protective equipment such as face masks and hand sanitizers and distribute them to the residents.
5. Strengthen hygiene measures, including thorough cleaning of the environment, prompt waste disposal, and daily ventilation and disinfection.
6. Check body temperature and symptoms related to COVID-19 every day. Ensure rapid quarantine of potentially contagious persons and a prompt notification to the health officials.
7. Provide education on prevention of infection and encourage good hygiene and health habits.

How to prevent infection by 2019-nCoV in canteens?

1. Canteens should encourage dining in batches and at off-peak meal times to reduce interaction between diners. During meals, one should avoid face-to-face contact or conversation and should shorten meal times. Diners can also take meals out and use personal cutlery to eat alone; should wash hands before eating and, if eating in a canteen, keep the mask on until sitting down to eat.
2. Canteens should strengthen personal protection for their employees. In addition to regular protective equipment such as uniforms and hats, all cooks in the kitchen and waiters in the hall should wear masks and single-use gloves and should replace them regularly.
3. Every morning, canteens should take employees' temperature and screen them for symptoms of fever (over 37.3ºC), cough, and fatigue. Ensure rapid quarantine and treatment of employees with such symptoms and disinfect the environment and articles that they had contacted with. Workers with diarrhea, hand injury or other diseases that may affect food safety should be transferred away from their post.

What are notifiable and quarantinable contagious diseases?

Notifiable contagious disease refers to any of various communicable health conditions that upon detection are required to be reported to local public health authorities in a timely manner. For these diseases, mandatory disease reporting plays a critical role in helping the authority to prevent and control the spread of disease in populations.

Quarantinable contagious diseases refer to contagious diseases that are highly contagious and have a high fatality rate, such as plague, cholera, and yellow fever.

In accordance with the Law of the People's Republic of China on the Prevention and Treatment of Contagious Diseases, China's health authorities have instituted management of quarantinable contagious diseases for COVID-19 based on the current understanding of its etiology, epidemiology and clinical characteristics. Control of ports, customs, and transportation links according to such management could reduce transmission through humans, animals, and articles.

The principle of China towards the control and prevention of contagious diseases are as follows: (1) prevention first, (2) equal emphasis on both prevention and treatment, (3) classified management of different kinds of contagious diseases, and (4) relying on scientific evidence and the concerted efforts of the public.

How has COVID-19 been classified as a contagious disease, and has this changed?

Initial Classification (2020): When COVID-19 first emerged, many countries implemented their strictest disease control measures:

1. In China, COVID-19 was classified as a Class B contagious disease but managed with Class A control measures (the strictest level, same as plague and cholera) due to its unknown nature and substantial public health risk.
2. This classification enabled rapid notifications, mandatory reporting, and strict quarantine measures to control the initial outbreak.

Reclassification (2023): As the pandemic evolved, classifications were updated:

• WHO: In May 2023, the World Health Organization declared that COVID-19 no longer constitutes a Public Health Emergency of International Concern (PHEIC), though it remains a global health threat.
• China: In January 2023, China downgraded COVID-19 management from Class A to Class B measures, removing mandatory quarantine and mass testing requirements.
• United States: The U.S. ended its COVID-19 Public Health Emergency in May 2023.

Current Status: While emergency declarations have ended, COVID-19 continues to circulate and cause illness. Vaccination, testing, and treatment remain important, and public health authorities continue to monitor for new variants.

What is a "super-spreader"?

A virus in an infected person can mutate or adapt to the conditions of the human body such that it can infect close contacts more easily. Patients carrying such a virus are called super-spreaders.

If the number of people infected by a patient exceeds three, such patient might be considered a super-spreader; if the number of people infected by a patient exceeds ten, such patients are super-spreaders.

Super-spreaders are also known as "King of viral infection" (Du Wang) in Chinese. The second meaning of "King of viral infection" is that the patients infected by these super-spreaders usually exhibit more severe symptoms and many patients may even die. The super-virulence of the virus spread by a super-spreader is the result of an increased infectivity and pathogenicity due to viral mutations.

What is the asymptomatic infection?

It refers to an infection where people with infections are asymptomatic and their physical examination findings could be normal. Often, when the pathogens are reproducing and incubating in the patient body, there is no clinical symptoms or abnormal signs. Without laboratory tests, he/she cannot be diagnosed. Persons with asymptomatic infections, including those of 2019-nCoV, are potential spreaders of the pathogen.

What is quarantine for medical observation?

According to the Law of the People's Republic of China on Prevention and Treatment of Contagious Diseases, close contacts with individuals known or suspected to be infected with the virus should undergo a medical observation or other preventive measures at the designated places.

The key management measures for close contacts include:

1. Register them for medical observation for seven to fourteen days.
2. They should avoid unnecessary outdoor activities.
3. They should be followed up every day by the disease prevention authority to assess and record body temperature and any symptoms related to COVID-19.

How to transport critically ill patients with infections?

For critically ill patients confirmed as 2019-nCoV positive, one should call the local emergency for an arrangement of ambulance transportation. The companion of the patients should wear a mask and protective suits for personal protection. Negative pressure ambulances should be used to prevent spreading the virus in the air. At negative pressure relative to the surrounding areas, air in the ambulance can be filtered and purified before emission, thus minimizing cross infection among the medical staff during treatment and transport of patients. Therefore, technically speaking, negative pressure ambulances are currently the most desirable vehicles for transport of patients with infections.

How do COVID-19 vaccines work?

COVID-19 vaccines teach your immune system to recognize and fight the SARS-CoV-2 virus without causing infection. Different vaccine types work in different ways:

1. mRNA vaccines (Pfizer-BioNTech, Moderna): Deliver genetic instructions (mRNA) to cells to produce the spike protein found on the virus surface. The immune system recognizes this protein as foreign and creates antibodies. The mRNA is quickly broken down and never enters the cell nucleus or interacts with your DNA.
2. Viral vector vaccines (Johnson & Johnson, AstraZeneca): Use a harmless modified virus (not SARS-CoV-2) to deliver genetic instructions for making the spike protein. The vector virus cannot replicate or cause disease.
3. Protein subunit vaccines (Novavax): Contain purified spike proteins along with an adjuvant (immune booster). The immune system responds to these proteins directly.
4. Inactivated virus vaccines (Sinovac, Sinopharm): Use killed virus particles that cannot cause infection but can trigger an immune response.

All approved vaccines have undergone rigorous clinical trials demonstrating their safety and effectiveness in preventing severe illness, hospitalization, and death.

Are COVID-19 vaccines safe?

Yes, COVID-19 vaccines have been proven safe through extensive clinical trials and ongoing monitoring of billions of doses administered worldwide.

Safety monitoring includes:

• Clinical trials: Vaccines were tested in tens of thousands of participants before authorization.
• Regulatory review: Multiple independent expert panels reviewed all safety and efficacy data.
• Ongoing surveillance: Systems like VAERS (US), Yellow Card (UK), and similar programs worldwide continuously monitor for adverse events.

Common side effects are typically mild and temporary:

• Pain, redness, or swelling at the injection site
• Fatigue, headache, muscle pain
• Fever, chills
• Nausea

Rare serious side effects: Very rare cases of myocarditis (heart inflammation), blood clots (with certain vaccines), and severe allergic reactions have been reported. Health authorities continuously assess risks versus benefits. For most people, the benefits of vaccination far outweigh the small risks.

Who should get vaccinated against COVID-19?

COVID-19 vaccination is recommended for most people. Specific recommendations may vary by country and are updated as new evidence emerges.

General recommendations:

• Primary series: Recommended for everyone aged 6 months and older (age cutoffs may vary by country and vaccine type).
• Boosters: Recommended for most people, especially those at higher risk of severe disease. Updated boosters targeting current variants are available.
• High-priority groups: Elderly, immunocompromised individuals, healthcare workers, and those with underlying conditions should stay current with vaccinations.

Special considerations:

• Pregnant women: Vaccination is recommended during pregnancy to protect both mother and baby.
• Immunocompromised: May need additional doses; consult healthcare provider.
• Previous infection: Vaccination is still recommended as it provides additional protection.
• Allergies: Those with severe allergies should consult their healthcare provider. Severe allergy to vaccine components is a contraindication.

Consult your healthcare provider or local health authority for personalized recommendations.

Do I need a COVID-19 booster shot?

Booster shots are recommended to maintain protection against COVID-19, as immunity from the primary vaccine series wanes over time, and new variants may partially evade prior immunity.

Why boosters are important:

• Restore waning immunity from initial vaccination or infection
• Improve protection against new variants
• Reduce risk of severe illness, hospitalization, and death
• May reduce transmission to others

Updated boosters: Health authorities periodically update booster formulations to better match circulating variants, similar to annual flu shots. As of 2023-2024, updated boosters targeting recent Omicron subvariants are available.

Timing: Recommendations for booster timing vary by country, age group, and risk factors. Generally, boosters are recommended at least 2-4 months after your last dose, depending on the specific situation.

Check with your local health authority for current booster recommendations specific to your situation.

What are COVID-19 variants and why do they matter?

Variants are versions of the SARS-CoV-2 virus that have accumulated genetic mutations. All viruses mutate over time as they replicate, and some mutations can affect the virus's characteristics.

Why variants matter:

• Transmissibility: Some variants spread more easily than others (e.g., Omicron spreads much faster than the original strain).
• Severity: Variants may cause more or less severe disease (e.g., Omicron generally causes less severe illness than Delta).
• Immune evasion: Mutations in the spike protein may help the virus partially evade immunity from vaccination or prior infection.
• Treatment effectiveness: Some variants may be less susceptible to certain treatments, particularly monoclonal antibodies.

Variant classification: The WHO classifies variants as:

• Variants of Concern (VOC): Have significant impact on public health (increased transmissibility, severity, or immune evasion).
• Variants of Interest (VOI): Have mutations that may affect characteristics but with limited evidence.
• Variants Under Monitoring (VUM): Being tracked but not yet showing concerning properties.

What are the major COVID-19 variants that have emerged?

Several significant variants have emerged since the original Wuhan strain:

1. Alpha (B.1.1.7) - First identified in the UK (late 2020). Approximately 50% more transmissible than the original strain.
2. Beta (B.1.351) - First identified in South Africa (late 2020). Showed some ability to evade immunity.
3. Gamma (P.1) - First identified in Brazil (late 2020). Similar immune evasion properties to Beta.
4. Delta (B.1.617.2) - First identified in India (late 2020, dominant in 2021). Highly transmissible, caused more severe disease, became globally dominant before Omicron.
5. Omicron (B.1.1.529) - First identified in South Africa (November 2021). Extremely transmissible with significant immune evasion, but generally causes less severe disease. Has spawned many subvariants (BA.1, BA.2, BA.4, BA.5, XBB, EG.5, JN.1, etc.).

Since late 2021, Omicron and its subvariants have been dominant worldwide. New subvariants continue to emerge and are monitored by health authorities.

How can I protect myself against new variants?

The fundamental prevention strategies remain effective against variants:

1. Stay up to date with vaccinations: Updated boosters are designed to provide better protection against current variants. Vaccines continue to offer strong protection against severe illness and death, even with variants.
2. Wear well-fitted masks: High-quality masks (N95, KN95, KF94) provide better protection, especially in high-risk indoor settings. Proper fit is crucial.
3. Improve ventilation: Increase fresh air exchange in indoor spaces; use air purifiers with HEPA filters where possible.
4. Practice hand hygiene: Regular handwashing and avoiding touching your face remain important.
5. Test when symptomatic: Rapid antigen tests are widely available for home use. Test if you have symptoms or known exposure.
6. Stay informed: Follow guidance from WHO, CDC, or your local health authority as recommendations may change with new variants.
7. Seek early treatment if infected: Antiviral treatments are most effective when started early (within 5 days of symptoms).

While no prevention method is 100% effective, layering multiple strategies provides the best protection against all variants.

What is Long COVID?

Long COVID, also known as Post-COVID Conditions (PCC) or Post-Acute Sequelae of SARS-CoV-2 (PASC), refers to a wide range of health problems that persist or develop weeks to months after the initial COVID-19 infection.

Key characteristics:

• Symptoms last 4 weeks or more after initial infection
• Can occur regardless of initial illness severity—even mild or asymptomatic cases can develop Long COVID
• Affects multiple organ systems
• Estimated to affect 10-30% of people who had COVID-19, though estimates vary

Common symptoms include:

• Fatigue: Persistent, debilitating tiredness not relieved by rest
• Cognitive dysfunction: "Brain fog," difficulty concentrating, memory problems
• Respiratory: Shortness of breath, persistent cough
• Cardiovascular: Heart palpitations, chest pain
• Neurological: Headaches, dizziness, changes in smell/taste, sleep problems
• Musculoskeletal: Joint and muscle pain
• Mental health: Depression, anxiety
• Other: Digestive issues, skin rashes, changes in menstrual cycles

Post-exertional malaise (PEM)—worsening of symptoms after physical or mental effort—is a hallmark symptom for many Long COVID patients.

How is Long COVID treated and what should I do if I have it?

There is currently no specific cure for Long COVID, but many symptoms can be managed, and most people improve over time.

If you suspect you have Long COVID:

1. Seek medical evaluation: Talk to your healthcare provider. They can rule out other conditions and help develop a management plan.
2. Track your symptoms: Keep a symptom diary to identify patterns and triggers.
3. Pace yourself: Avoid pushing through fatigue, which can worsen symptoms. Rest when needed.
4. Consider specialized care: Many hospitals now have Long COVID clinics with multidisciplinary teams.

Treatment approaches:

• Symptom management: Medications and therapies targeted at specific symptoms (pain, sleep, breathing difficulties, etc.)
• Rehabilitation: Physical therapy, occupational therapy, pulmonary rehabilitation as appropriate
• Pacing strategies: Learning to manage energy to avoid post-exertional malaise
• Mental health support: Counseling, support groups, treatment for anxiety or depression
• Lifestyle modifications: Adequate rest, gentle activity as tolerated, healthy diet, stress management

Prevention: The best way to prevent Long COVID is to avoid COVID-19 infection through vaccination, masks, ventilation, and other precautions. Vaccination before or after infection may reduce the risk of Long COVID.

Research on Long COVID is ongoing, and new treatments may become available. Stay in touch with your healthcare provider for the latest guidance.