The number of doses need depends on what vaccine you receive. To get the most protection:
- Two doses of the Pfizer-BioNTech doses should be given three weeks (21 days) apart
- Two doses of the Moderna doses should be given one month (28 days) apart
- Johnson & Johnson’s Janssen is one doseCOVID-19 vaccine requires just one dose
If you are receiving the Pfizer or Moderna vaccine, you should get your second shot as close to the recommended three-week or one-month interval as possible. However, your second dose may be given up to six weeks (42 days) after the first dose, if necessary. You should not get the second dose earlier than the recommended interval.
People with moderately to severely compromised immune systems should receive an additional dose of mRNA COVID-19 vaccine after the initial two doses.