On August 24, 2021, the Centers for Disease Control (CDC) approved the U.S. Food and Drug Administration (FDA) recommendation for Pfizer booster for certain groups.

On August 12, 2021, the U.S. Food and Drug Administration (FDA) amended the emergency use authorizations (EUAs) for both the Pfizer-BioNTech COVID-19 Vaccine and the Moderna COVID-19 Vaccine to allow for the use of a third dose in certain immunocompromised individuals.

The  (CDC) approved this recommendation.

Difference between an additional dose and a booster shot

  • An additional dose is for people who may not have had a strong enough immune response from the first 2 doses.
  • A booster shot is for people whose immune response may have weakened over time.

Who can get an additional Pfizer or Moderna vaccine dose

Immunocompromised individuals include the following:

  • Recent or current treatment of a solid tumor or hematologic malignancy
  • Solid-organ, chimeric antigen receptor (CAR-T), or stem cell transplant within the last 2 years
  • Moderate to severe primary immunodeficiency (PID)
  • Advanced or untreated HIV
  • Active treatment with high-dose corticosteroids (i.e., ≥20 mg prednisone or equivalent per day), alkylating agents, antimetabolites, transplant-related immunosuppressive drugs, cancer chemotherapeutic agents classified as severely immunosuppressive, tumor necrosis factor (TNF) blockers, and other biologic agents that are immunosuppressive or immunomodulatory
  • Based on clinician assessment of need, chronic medical conditions associated with immunosuppression (e.g., asplenia, chronic renal disease).

There are no recommendations yet for other fully vaccinated individuals or recipients of Johnson & Johnson’s vaccine manufactured under its Janssen vaccine division.

The additional dose of an mRNA COVID-19 vaccine should be administered at least four weeks (28 days) after the second dose of the Pfizer-BioNTech COVID-19 vaccine or Moderna COVID-19 vaccine.

Patients should try to match the vaccine with the primary series, but the other mRNA COVID-19 vaccine product may be administered if that is not possible.

Antibody testing and T cell testing are not recommended to evaluate the need for an additional dose of the vaccine because the utility of such testing is not known.