The CDC now recommends individuals who are moderately to severely immunocompromised get three primary doses followed by a booster shot five months later. This population is the only group eligible to receive four doses at this time. The fourth dose is the booster for people in this group who have already received three shots of the primary dose of either the Pfizer-BioNTech or Moderna vaccine.
Given the recommendation, immunocompromised individuals above the age of 18 who received their additional primary mRNA vaccine dose in August 2021 may now be eligible for their booster dose this month (January 2022).
Individuals are encouraged to talk to a healthcare provider regarding eligibility.
As a reminder, for immunocompromised people who received a single shot of Johnson & Johnson COVID-19 vaccine, the CDC does not recommend additional primary doses, but advises that they get a booster shot of the Moderna or Pfizer-BioNTech vaccines two months after the first dose.