People with COVID-19 have reported a wide range of symptoms, ranging from mild symptoms to severe illness. Symptoms may appear 2 to 14 days after exposure to the virus. Symptoms may include: fever or chills; cough; shortness of breath; fatigue; muscle or body aches; headache; new loss of taste or smell; sore throat; congestion or runny nose; nausea or vomiting; diarrhea.

Adults who have a past history of symptoms consistent with COVID-19 but who did not have laboratory confirmation of COVID-19 with a viral diagnostic test (RT-PCR or antigen) and who present with new symptoms consistent with COVID-19 should be tested and undergo quarantine.

Yes. During the recovery process, people with COVID-19 might experience recurring symptoms alternating with periods of feeling better. Varying degrees of fever, fatigue and breathing problems can occur, on and off, for days or even weeks.

Coronavirus disease is a respiratory illness that can spread from person to person. The virus is thought to spread mainly between people who are in close contact with one another (within about 6 feet) through respiratory droplets produced when an infected person coughs or sneezes.

Viruses are named based on their genetic structure to facilitate the development of diagnostic tests, vaccines and medicines. Virologists and the wider scientific community do this work, so viruses are named by the International Committee on Taxonomy of Viruses (ICTV).

All available evidence for COVID-19 suggests that SARS-CoV-2 has a zoonotic source.

Six species of human coronaviruses are known, with one species subdivided into two different strains, making seven strains of human coronaviruses altogether.

The final name of the disease will be provided by the International Classification of Diseases (ICD). WHO is also proposing ‘2019-nCoV’ as an interim name of the virus. The final decision on the official name of the virus will be made by the International Committee on Taxonomy of Viruses.

Soreness and swelling at the injection site are common reactions to the Moderna and Pfizer-BioNTech COVID-19 vaccines. Sometimes, these common symptoms are followed by a less-common itchy rash and other symptoms. This later reaction is known as COVID arm.

Take up a relaxation practice. When stressors throw your nervous system out of balance, relaxation techniques such as deep breathing, meditation, and yoga can bring you back into a state of equilibrium. Regular practice delivers the greatest benefits, so see if you can set aside even a little time every day.

Smoking waterpipes, also known as shisha or hookah, often involves the sharing of mouth pieces and hoses, which could facilitate the transmission of the COVID-19 virus in communal and social settings.

Tobacco smoking is a known risk factor for many respiratory infections and increases the severity of respiratory diseases. A review of studies by public health experts convened by WHO on 29 April 2020 found that smokers are more likely to develop severe disease with COVID-19, compared to non-smokers.

• Current evidence suggests that the virus spreads mainly between people who are in close contact with each other, typically within 1 metre (short-range). A person can be infected when aerosols or droplets containing the virus are inhaled or come directly into contact with the eyes, nose, or mouth.

It is not certain how long the virus that causes COVID-19 survives on surfaces, but it seems likely to behave like other coronaviruses. A recent review of the survival of human coronaviruses on surfaces found large variability, ranging from 2 hours to 9 days (11).The survival time depends on a number of factors, including the type of surface, temperature, relative humidity and specific strain of the virus.

The most recent common ancestor (MRCA) of all coronaviruses is estimated to have existed as recently as 8000 BCE, although some models place the common ancestor as far back as 55 million years or more, implying long term coevolution with bat and avian species.

There is no evidence that the Bacille Calmette-Guérin vaccine (BCG) protects people against infection with COVID-19 virus. Two clinical trials addressing this question are underway, and WHO will evaluate the evidence when it is available. In the absence of evidence, WHO does not recommend BCG vaccination for the prevention of COVID-19. WHO continues to recommend neonatal BCG vaccination in countries or settings with a high incidence of tuberculosis.

Coronaviruses die very quickly when exposed to the UV light in sunlight. Like other enveloped viruses, SARS-CoV-2 survives longest when the temperature is at room temperature or lower, and when the relative humidity is low (<50%).

The lungs are the organs most affected by COVID-19 because the virus accesses host cells via the receptor for the enzyme angiotensin-converting enzyme 2 (ACE2), which is most abundant on the surface of type II alveolar cells of the lungs.

• Avoid touching surfaces, especially in public settings or health facilities, in case people infected with COVID-19 have touched them. Clean surfaces regularly with standard disinfectants.• Frequently clean your hands with soap and water, or an alcohol-based hand rub.

Most people infected with the COVID-19 virus will experience mild to moderate respiratory illness and recover without requiring special treatment. Older people, and those with underlying medical problems like cardiovascular disease, diabetes, chronic respiratory disease, and cancer are more likely to develop serious illness.

People of all ages can be infected by the COVID-19 virus.Older people and younger people can be infected by the COVID-19 virus. Older people, and people with pre-existing medical conditions such as asthma, diabetes, and heart disease appear to be more vulnerable to becoming severely ill with the virus.

The most likely ecological reservoirs for SARS-CoV-2 are bats, but it is believed that the virus jumped the species barrier to humans from another intermediate animal host. This intermediate animal host could be a domestic food animal, a wild animal, or a domesticated wild animal which has not yet been identified.

The ill person should stay in a separate room. If this is not possible, then keep at least a 1-metre distance from them. The sick person and anyone else in the same room should wear a medical mask.Provide good ventilation in the room of the ill person and shared spaces, and open windows if possible and safe to do so.

Currently, there is no evidence about the survival of the COVID-19 virus in drinking-water or sewage. The morphology and chemical structure of the COVID-19 virus are similar to those of other human coronaviruses for which there are data about both survival in the environment and effective inactivation measures.

Those who may have been exposed to someone with COVID-19 and those who have recently travelled to a country or region with the widespread transmission have been advised to self-quarantine for 14 days from the time of last possible exposure.

So far, data suggests that children under the age of 18 years represent about 8.5% of reported cases, with relatively few deaths compared to other age groups and usually mild disease. However, cases of critical illness have been reported. As with adults, pre-existing medical conditions have been suggested as a risk factor for severe disease and intensive care admission in children.Further studies are underway to assess the risk of infection in children and to better understand transmission in this age group.

WHO recommends that mothers with suspected or confirmed COVID-19 should be encouraged to initiate or continue to breastfeed. Mothers should be counselled that the benefits of breastfeeding substantially outweigh the potential risks for transmission.

The COVID-19 virus has not been detected in drinking-water supplies, and based on current evidence, the risk to water supplies is low.