What is COVID-19 and how can I protect myself?
Answer From Pritish K. Tosh, M.D.
A new virus called the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was identified as the cause of a disease outbreak that began in China in 2019. The disease is called coronavirus disease 2019 (COVID-19).
In March 2020, the World Health Organization (WHO) declared COVID-19 a pandemic. Public health groups, including the U.S. Centers for Disease Control and Prevention (CDC) and WHO, are monitoring the pandemic and posting updates on their websites. These groups have also issued recommendations for preventing the spread of the virus.
How does the coronavirus spread?
Data has shown that the virus that causes coronavirus disease 2019 (COVID-19) mainly spreads from person to person among those in close contact (within about 6 feet, or 2 meters). The virus spreads by respiratory droplets released when someone infected with the virus coughs, sneezes, breathes, sings or talks. These droplets can be inhaled or land in the mouth, nose or eyes of a person nearby.
Sometimes the COVID-19 virus can spread when a person is exposed to small droplets that stay in the air for several minutes or hours — called airborne transmission. It's not yet known how common it is for the virus to spread this way.
It can also spread if a person touches a surface with the virus on it and then touches his or her mouth, nose or eyes, but this isn't a main way it spreads.
What are the symptoms of COVID-19?
COVID-19 symptoms can be very mild to severe. Some people have no symptoms. The most common symptoms are fever, cough and tiredness.
Other symptoms may include shortness of breath, muscle aches, chills, sore throat, headache, chest pain, and loss of taste or smell. This list is not all inclusive. Other less common symptoms have also been reported. Symptoms may appear two to 14 days after exposure.
Can COVID-19 be prevented?
The U.S. Food and Drug Administration (FDA) has given emergency use authorization to some COVID-19 vaccines in the U.S. A vaccine might prevent you from getting COVID-19 or prevent you from becoming seriously ill from COVID-19 if you get the COVID-19 virus.
What can I do to avoid becoming ill?
The best way to prevent illness is to avoid being exposed to the COVID-19 virus. The CDC and WHO recommend following these precautions:
- Keep at least 6 feet (2 meters) of distance between yourself and people outside your household.
- Avoid crowds and indoor places that have poor ventilation.
- Wash your hands often with soap and water for at least 20 seconds, or use an alcohol-based hand sanitizer that contains at least 60% alcohol.
- Wear a mask in public places, especially when social distancing is difficult.
- Cover your mouth and nose with your elbow or a tissue when you cough or sneeze. Throw away the used tissue. Wash your hands right away.
- Avoid touching your eyes, nose and mouth.
- Clean and disinfect surfaces you often touch on a daily basis.
If you have a chronic medical condition and may have a higher risk of serious illness, check with your doctor about other ways to protect yourself.
Should I wear a mask?
The CDC and WHO recommend that people wear cloth face masks in public when social distancing is difficult. This advice is based on evidence that people with COVID-19 can transmit the COVID-19 virus before they realize they have it.
Using masks in public may help reduce the spread from people who don't have symptoms. Non-medical cloth masks are recommended for the public. Surgical masks may be used if available. In some locations, surgical masks and N-95 respirators are in short supply and should be reserved for health care providers.
After you're fully vaccinated, the CDC recommends that it's ok not to wear a mask in several situations when you're outside. For example, you can attend small outdoor gatherings with family and friends, and dine outdoors at restaurants without wearing a mask. You're considered fully vaccinated 2 weeks after you get a second dose of an mRNA COVID-19 vaccine or 2 weeks after you get a single dose of the Janssen/Johnson & Johnson COVID-19 vaccine.
However, even if you're fully vaccinated, continue to wear a face mask in indoor public spaces and outdoors where there is a high risk of COVID-19 transmission, such as at a crowded event. In the U.S., you'll also need to wear a mask while on planes, buses, trains and other forms of public transportation.
Can I travel?
If you're planning to travel, first check for travel advisories and use appropriate precautions when in public. You also may want to talk with your doctor if you have health conditions that make you more susceptible to respiratory infections and complications.
What can I do if I am or may be ill with COVID-19?
If you develop symptoms or you've been exposed to the COVID-19 virus, contact your doctor for medical advice. If you need to go to the doctor or hospital, call ahead so health care providers can take steps to ensure that others aren't exposed.
Take the following precautions to avoid spreading the COVID-19 virus:
- Stay home from work, school and public areas, except to get medical care.
- Avoid public transportation, taxis and ride-sharing if possible.
- Wear a cloth face mask around other people.
- Isolate yourself as much as possible from others in your home.
- Use a separate bedroom and bathroom if possible.
- Avoid sharing dishes, glasses, bedding and other household items.
April 30, 2021
Pritish K. Tosh, M.D.
See more Expert Answers
- Coronavirus disease 2019 (COVID-19). U.S. Centers for Disease Control and Prevention. https://www.cdc.gov/coronavirus/2019-nCoV/index.html. Accessed Feb. 18, 2021.
- Coronavirus disease (COVID-19) advice for the public. World Health Organization. https://www.who.int/emergencies/diseases/novel-coronavirus-2019/advice-for-public. Accessed June 26, 2020.
- AskMayoExpert. COVID-19: Adult. Mayo Clinic; 2020.
- Chu DK, et al. Physical distancing, face masks, and eye protection to prevent person-to-person transmission of SARS-CoV-2 and COVID-19: A systematic review and meta-analysis. Lancet. 2020; doi: 10.1016/S0140-6736(20)31142-9.
- Vaccines and related biological products advisory committee meeting. U.S. Food and Drug Administration. https://www.fda.gov/media/144245/download. Accessed Dec. 9, 2020.
- Emergency use authorization. U.S. Food & Drug Administration. https://www.fda.gov/emergency-preparedness-and-response/mcm-legal-regulatory-and-policy-framework/emergency-use-authorization#coviddrugs. Accessed March 1, 2021.
- Choosing safer activities. Centers for Disease Control and Prevention. https://www.cdc.gov/coronavirus/2019-ncov/daily-life-coping/participate-in-activities.html. Accessed April 27, 2021.
- When you’ve been fully vaccinated. Centers for Disease Control and Prevention. https://www.cdc.gov/coronavirus/2019-ncov/vaccines/fully-vaccinated.html. Accessed April 27, 2021.