It depends how old you are and if you are immunocompromised.
For everyone 5 and over:
The mRNA vaccines (also known by their manufacturers’ names, Pfizer and Moderna) need two doses plus a booster to be most effective. The first shot starts building protection against COVID-19. A second shot given 3 or 4 weeks later (depending on which vaccine you get) is needed to get the best protection from the vaccine.
- Pfizer COVID-19 vaccine doses should be given 3 weeks (21 days) apart
- Moderna COVID-19 vaccine doses should be given 4 weeks (28 days) apart
You should get your second dose as close to the recommended 3-week or 4-week interval as possible. However, if necessary, your second dose may be given up to 6 weeks (42 days) after the first dose. You should not get the second dose earlier.
For babies and children under 5:
- Three doses of the Pfizer vaccine, with dose two 21 days after the first dose and dose three at least 8 weeks (2 months) after the second dose.
- Two doses of the Moderna vaccine, with dose two 28 days after the first dose.
Adults 18+ also have the option to get the Novavax vaccine in two doses three weeks apart, or (in some cases) the J&J vaccine. Talk to your doctor if you have concerns or questions about the different types of vaccines.
If you or your child has a moderately or severely weakened immune system and got two doses of vaccine, you should get an additional primary dose of the same COVID vaccine, 28 or more days later. This third dose of COVID vaccine should be considered part of your or your child’s primary COVID vaccine series, not a booster dose. This third dose should help increase your immunity, which was likely lower than people who are not immunocompromised.
Do I need a booster dose?
Everyone 5 years and older who got vaccinated against COVID, including pregnant and recently pregnant people, is now recommended to get a booster shot. People 50 and older and those 12+ who are immunocompromised should get a second booster 4 months after the first. More details below.