People who are moderately to severely immunocompromised are especially vulnerable to COVID-19 because they are more at risk of serious, prolonged illness. Studies indicate some immunocompromised people don’t always build the same level of immunity after vaccination the way non-immunocompromised people do.
CDC recommends that people with moderately to severely compromised immune systems receive an additional dose of mRNA COVID-19 vaccine at least 28 days after a second dose of Pfizer-BioNTech COVID-19 vaccine or Moderna COVID-19 vaccine.
CDC does not recommend additional doses or booster shots for any other population at this time.
To learn more, visit https://www.cdc.gov/coronavirus/2019-ncov/vaccines/recommendations/immuno.html.