Different COVID-19 Vaccines

Additional Recommendations for Immunocompromised People
Additional primary dose: Moderately to severely immunocompromised people who are 12 years and older and received a Pfizer-BioNTech primary series or 18 years and older and received a Moderna primary series should receive an additional primary dose of the same vaccine at least 28 days after their second dose.
Booster dose: Moderately to severely immunocompromised people who are 18 years of age and older and received a Pfizer-BioNTech or Moderna primary series are also eligible for a booster dose at least 6 months after their additional primary dose, using any of the three COVID-19 vaccines.
Immunocompromised people who received a J&J/Janssen vaccine are not recommended to receive an additional primary dose, but should receive a booster dose at least 2 months after their initial dose, using any of the three COVID-19 vaccines.