“Why do I have to wear a mask? I’m vaccinated.”

February 23, 2021 in Disease Management  •  By Miles Varn, MD

With vaccines to protect against COVID-19 now available and a small but growing number of Americans having received one or both doses of the vaccine, one question that keeps coming up is, “If I’m vaccinated, why do I still need to wear a mask?”

There are several reasons why wearing a mask, continuing to practice social distancing from people you don’t live with, limiting time indoors in poorly ventilated spaces and in crowds, and regular, thorough hand washing are still needed at this point in the pandemic.

  • Vaccines don’t provide immediate protection. It takes some time for any vaccine to provoke an immune response from your body’s immune system. For the currently available COVID-19 vaccines, researchers have found that the vaccines don’t start providing protection until about 12 to 14 days after you receive your first shot. At that point, the vaccines are only about 50% effective. Two weeks after the second shot of vaccines that require two doses, effectiveness reaches between 94% and 95%. With continuing high numbers of cases in a large number of communities across the U.S., 95% protection may not be adequate to prevent you from contracting the virus if you no longer wear a mask or follow other guidelines. In addition, since both the virus and the vaccines are new, we don’t know how long the immunity that vaccines confer will last.
  • You may still be able to spread the virus. To date, researchers do not have enough data to know whether, in addition to preventing infection, the current COVID-19 vaccines also prevent transmission of the virus. The flu vaccine, for example, prevents you from getting sick but does not prevent you from becoming infected and passing the virus to others unintentionally. Wearing a mask after receiving a COVID-19 vaccine is an important way to help protect people who are not yet vaccinated, which at this point in time is the majority of people in the U.S., as well as people who cannot be vaccinated, such as those who have had a severe allergic reaction to ingredients in the new vaccines.
  • You’ll be protecting people who are immunocompromised. Some studies have found that for people living with cancer, the current vaccines may not confer protection against becoming ill. These people are already at a higher risk of becoming seriously ill, so it’s essential to limit their potential exposure to virus. Other people with weakened immune systems who may be at an increased risk and for whom vaccines may not offer high levels of protection include those who take immunosuppressant drugs after an organ transplant and people with chronic health conditions that affect immunity, including lupus, rheumatoid arthritis, HIV infection, and type 1 diabetes. To date, the data on vaccine effectiveness for these people is limited.
  • We don’t know how effective current vaccines are against new variants. As the virus continues to mutate, some research suggests that the variants may be more contagious or may reduce the effectiveness of some of the vaccines at their current dosages. Wearing a mask can help lower your risk of being exposed to these variants.