What is COVID-19?

This article was last reviewed and updated on January 12, 2022.

Coronavirus disease 2019 (COVID-19) is caused by a coronavirus called SARS-CoV-2. A coronavirus is a type of virus that causes respiratory tract infections, such as colds and pneumonia. Although coronaviruses usually cause mild symptoms, they can (on rare occasions) cause life-threatening breathing difficulties and death.

How to protect yourself from COVID-19

Get vaccinated

To find a vaccine near you:

  • Text your zip code to 438829
  • Check https://www.vaccines.gov/
  • Call 1-800-232-0233
  • Contact your state or local health department
  • Contact your local pharmacy or check their website


Know How it Spreads

COVID-19 is mainly spread:

  • When inhaling respiratory droplets produced by an infected person as they cough or sneeze.
  • When droplets or particles that contain the virus land on the mouth, nose or eyes after an infected person coughs or sneezes when standing in close proximity less than 6 feet apart.
  • When someone touches their mouth, nose, or eyes with unwashed hands that have the virus on them.
  • COVID-19 may be spread by contact with people who are not showing symptoms.
  • Note there is no current evidence that you can get COVID-19 infection by consuming food or drinking water.


Clean your hands often

  • Wash your hands with soap and water for at least 20 seconds, especially after visiting a public place and after blowing your nose, coughing, or sneezing.
  • If soap and water are not available, use a hand sanitizer that contains at least 60% alcohol.
  • Cover all surfaces of your hands and rub them together until they feel dry — wiping off your hands before the sanitizer is dry reduces its effectiveness.
  • Avoid touching your eyes, nose, and mouth with unwashed hands.


Avoid close contact

  • Avoid close contact with people who are sick.
  • If you are not fully vaccinated and age 2 years or older, the CDC recommends wearing a mask in indoor public places. Even if you are fully vaccinated, wear a mask in indoor public places if you are in an area of substantial or high transmission. Check the CDC site for the data in your area https://covid.cdc.gov/covid-data-tracker/#county-view.
  • Put responsible distance between yourself and other people. The recommended space, at this time, is at least six feet. This is especially important for people who are at higher risk of getting very sick.

Self-isolation: what is it, and why is it important?

Self-isolation is crucial in preventing the spread of COVID-19 to others. Find out more about what it really means, how to self-isolate, and helpful tips on how to cope when you’re stuck indoors.

Should I wear a facemask?

  • If you are 2 years and older, you should wear a mask in indoor public places if
    • you are not fully vaccinated
    • you have a weakened immune system
    • you are in an area of substantial or high transmission
  • If you are in an area with high numbers of COVID-19 cases, you should wear a mask in crowded outdoor settings or during activities where you are in close contact with people who are not fully vaccinated.
  • A mask should fit snugly and around the sides of your face and should cover your nose and mouth completely. This is important if you must go to grocery stores, pharmacies or other public places where it is difficult to stay at least 6 feet away from other people. You should also wear a face mask at home if you live with someone who has symptoms of COVID-19 or has tested positive for COVID-19. See the latest CDC recommendations on face masks.2
  • If you are sick, you should wear a facemask when you are around other people (e.g., sharing a room or vehicle) and if you need to go out to see a healthcare provider. Learn what to do if you are sick.
  • Even if you are fully vaccinated, you are still required to wear a mask
    • on all planes, buses, trains, and other forms of public transportation
    • in homeless shelters
    • in correctional facilities
    • in healthcare settings
  • The CDC also recommends that you wear a mask when around others and in public places for an additional 5 days after isolating following symptoms or a positive viral test.
    • If you live or work in a correctional or detention facility or a homeless shelter and are around someone who has COVID-19, you should still get tested, even if you don’t have symptoms.1

Vaccination Guidelines

  • You are considered fully vaccinated if
    • It has been 2 weeks since your second dose in a 2-dose series, such as the Pfizer or Moderna vaccines, or
    • It has been 2 weeks after a single-dose vaccine, such as Johnson & Johnson’s Janssen vaccine
  • Based on latest evidence, the CDC is expressing a clinical preference for people to get an mRNA COVID-19 vaccine (Pfizer-BioNTech or Moderna) over the Johnson & Johnson’s COVID-19 vaccine at this time. But those who are unable or unwilling to get an mRNA vaccine will still have access to Johnson & Johnson’s COVID-19 vaccine.4
  • The CDC recommends that everyone 12 years and older should get a booster shot. The CDC is also recommending that people 5 years and older that are moderately or severely immunocompromised should receive a third vaccine dose 28 days after their second shot.3
  • Even if you are fully vaccinated, you are still required to wear a mask
    • on all planes, buses, trains, and other forms of public transportation
    • in homeless shelters
    • in correctional facilities
    • in healthcare settings
  • If you are fully vaccinated and have a weak immune system, you should follow all recommendations for unvaccinated people until advised otherwise by your healthcare provider.
  • If you were exposed to someone with COVID-19, you should get tested at least 5 days after your contact and watch for symptoms until 10 days. You should also wear a well fitted face mask for 10 days and avoid being around people who are at high risk. If you develop symptoms, you should isolate immediately and get tested.5