Vaccine Boosters: A Year in Review for Our COVID–19 Vaccination

While Omicron-adapted vaccines were being developed, our original COVID–19 vaccine finds new life in booster doses and as first-line protection for the very young.

At the start of 2022, the Omicron variant was causing the greatest surge of COVID–19 cases yet.1 2

Fortunately, just days into the new year, the U.S. Food and Drug Administration (FDA) granted our request for emergency use authorization of a booster dose of our original COVID–19 vaccine for ages 12 years and older. The development and testing of new vaccines tailored specifically to the Omicron variant were underway here at Pfizer, but another solution was needed in the meantime. We would need to use our existing tools to help protect people of all ages against this persistent viral threat.

In March 2022, an additional (fourth) booster dose was authorized for anyone over the age of 65—a limit that was subsequently lowered to age 50—to help protect those at higher risk of developing severe COVID–19 disease.

In April 2022, the FDA authorized boosters for 5 through 11 years of age as well. During this time, a Phase 2/3 clinical trial was also underway to test a lower-strength version of our original COVID–19 vaccine as a three-dose primary series for children six months to under 5 years of age. With promising immune response data, the FDA granted an emergency use authorization for this age group in June.

"Between widespread pandemic fatigue and a leap in viral evolution, 2022 has not been an easy year as we continue to fight COVID–19, but I believe we at Pfizer have risen to the challenge," said Dr. Albert Bourla, Pfizer Chairman & Chief Executive Officer.

Emergency uses of the vaccines have not been approved or licensed by FDA but have been authorized by FDA under an Emergency Use Authorization (EUA) to prevent Coronavirus Disease 2019 (COVID-19) in individuals aged 6 months and older. The emergency uses are only authorized for the duration of the declaration that circumstances exist justifying the authorization of emergency use of the medical product under Section 564(b)(1) of the FD&C Act unless the declaration is terminated or authorization revoked sooner.

  1. World Health Organization. WHO Coronavirus (COVID–19) Dashboard. Available at: is external)
  2. Keyel AC, Russell A, Plitnick J, et al. SARS-CoV-2 Vaccine Breakthrough by Omicron and Delta Variants, New York, USA. Emerg Infect Dis. 2022;28(10):1990-1998. doi:10.3201/eid2810.221058