COVID-19 Booster Shots & Additional Doses

On August 12, 2021, the U.S. Food and Drug Administration (FDA) amended the emergency use authorizations (EUAs) for 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.

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

On October 21, 2021, the CDC expanded its recommendations for COVID-19 vaccine booster shots for certain populations to include the Moderna and Janssen (Johnson & Johnson) vaccines.  The FDA had earlier granted Emergency Use Authorization of the boosters.

The CDC also said eligible people can “mix and match” and choose to receive a booster vaccine that is different from the one(s) initially received.

In making its recommendation, the advisory panel stressed that people who have received two mRNA vaccine doses or a single Johnson & Johnson dose should still consider themselves fully vaccinated. Federal health officials said they would continue to study whether those who had weak immune systems and had already received a third dose of a vaccine should go on to get a booster shot

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 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)

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.

Who can get a booster?

  • A single COVID-19 vaccine booster dose at least six months after completion of an mRNA primary series for certain populations. The dose for the Moderna booster would be half that given during the primary series. The booster is recommended for individuals in the same risk groups identified when the Pfizer-BiNTech vaccine was approved last month, including those who are:
  • The use of a single booster dose of the Janssen (Johnson and Johnson) COVID-19 vaccine at least two months after completion of the single-dose primary regimen to anyone 18 years of age and older. The dose would be the same as the primary dose.

Find a COVID-19 Vaccine: Search vaccines.gov, text your ZIP code to 438829, or call 1-800-232-0233 to find locations near you.