Some COVID-19 vaccines require one dose and some require two doses as part of their primary series. Your health care provider will let you know which vaccine you are getting.
There are also recommendations for people with certain immunocompromising conditions to receive an additional dose as part of their primary series.
The two-dose COVID-19 vaccine schedule
Two doses are needed for the primary series of the Pfizer and Moderna COVID-19 vaccines. Your health care provider or the person giving you the vaccine will let you know when to get your second dose.
- The second dose of the Pfizer vaccine is given 3-8 weeks after the first dose.
- The second dose of the Moderna vaccine is given 4-8 weeks after the second dose.
New research suggests that people ages 12 to 64, particularly males age 12 to 39, may benefit from getting their second dose eight weeks after the first dose. A longer time between the first and second doses may increase the effectiveness of these vaccines, and minimize the small risk of heart problems, including myocarditis and pericarditis.
Some people should still get their second doses at three or four weeks. People ages 5 through 11 years, people 65 years and older, people at risk of severe disease, or anyone needing to develop protection quickly because of high levels of COVID-19 in their community should get the second dose of Pfizer COVID-19 vaccine three weeks after the first dose, or the second dose of Moderna COVID-19 vaccine four weeks after the first dose.
People who have already received their primary series and got the two doses three or four weeks apart do not need to repeat any doses.
It is important to get both vaccine doses of COVID-19 vaccine. The second dose increases your immunity to COVID-19 and provides longer protection. You should get the same product for the two doses in the primary series. Even if it is beyond the recommended amount of time between the two doses, go get your second dose. You will not have to start over.
We recommend that you schedule an appointment for your second dose when you get the first dose. Make sure you write down the appointment date somewhere you will remember.
Additional dose of mRNA vaccine for people with certain immunocompromising conditions
CDC recommends that people with certain immunocompromising conditions get an additional dose of an mRNA vaccine (Pfizer or Moderna) as part of their primary vaccine series.
If you received an mRNA vaccine (Pfizer or Moderna), you should get the same product that you received when you were initially vaccinated, and the additional dose should be given at least 28 days after your second dose of vaccine.
If you received a Johnson & Johnson vaccine, you should receive a second dose of an mRNA vaccine at least 28 days after your single Johnson & Johnson dose.
People should talk to their health care provider about their medical condition, and whether getting an additional dose is appropriate for them.