The timing between your first and second shots depends on which vaccine you received.
Certain groups of people who received both doses of the Pfizer-BioNTech COVID-19 Vaccine are eligible to get a Pfizer-BioNTech booster shot.
People with moderately to severely compromised immune systems should receive an additional dose of mRNA COVID-19 vaccine (i.e., Pfizer-BioNTech or Moderna) after the initial 2 doses.
If you have a weakened immune system due to other diseases or medications, you can receive a COVID-19 vaccine if you have not had a severe or immediate allergic reaction to any of the ingredients in the vaccine.
You should get your second shot even if you have side effects after the first shot, unless a vaccination provider or your doctor tells you not to get it.
If you received a Pfizer-BioNTech or Moderna COVID-19 vaccine, you should get the same product for your second shot.
COVID-19 vaccines are not interchangeable.
If you receive a Pfizer-BioNTech or Moderna COVID-19 vaccine, you will need 2 shots to get the most protection.
Learn more about who is eligible for a COVID-19 booster shot.