On March 29, 2022, the U.S. Food and Drug Administration (FDA) approved a second COVID-19 booster dose of either the Pfizer-BioNTech or the Moderna COVID-19 vaccine for older people and certain immunocompromised patients. A second booster dose of the FDA-authorized Pfizer-BioNTech COVID-19 vaccine and the FDA-approved Comirnaty can be given to individuals age 50 and older as well as immunocompromised patients age 12 and older who received a first booster dose at least 4 months ago. A second booster dose of the FDA-authorized Moderna COVID-19 Vaccine and the FDA-approved Spikevax is approved for individuals age 50 and older and for those age 18 and older who are immunocompromised and received their first booster dose at least 4 months ago. A first booster dose had previously been approved by the FDA for patients 12 and older who completed their primary series at least 2 months prior for Jansen (J&J) vaccine or at least 5 months prior for Pfizer-BioNTech or Moderna vaccine. This approval of a second booster dose was granted after evaluating safety and efficacy data submitted by Pfizer-BioNTech and Moderna that showed no new safety concerns in participants who received a second booster dose at least 4 months after receiving the first booster dose. An ongoing, open-label, non-randomized clinical study demonstrated increased antibody levels against SARS-CoV-2 virus (including delta and omicron variants) in participants who received a second booster dose, compared to participants who received their first booster dose 5 months prior. Vaccination still remains the most effective way to prevent infection with COVID-19. The FDA recommends vaccination with an FDA-approved or FDA-authorized COVID-19 vaccine and staying up to date with booster doses if eligible.