Data from a phase 1 study supporting the administration of a booster dose of the Pfizer-BioNTech COVID-19 vaccine (BNT162b2) have been submitted to the Food and Drug Administration (FDA).

The phase 1 study is part of a clinical trial program evaluating the safety, tolerability and immunogenicity of a booster dose of the Pfizer-BioNTech COVID-19 vaccine. The study included adult participants who received a 30mcg dose of the vaccine 8 to 9 months after receiving the second dose.

Results showed that the booster dose elicited significantly higher neutralizing antibodies against the wild type (5 to 8 times) and the Beta variant (15 to 21 times) compared with the levels observed after the 2-dose series. The booster dose was also found to elicit high neutralizing antibodies against the Delta variant of greater than 5-fold in individuals 18 to 55 years of age and greater than 11-fold in individuals 65 to 85 years of age, compared with the levels observed after the 2-dose series. 

Phase 3 data assessing the booster dose are expected shortly and will be submitted to the FDA as well as other regulatory authorities worldwide. The Companies plan to seek FDA approval of the third dose in individuals 16 years of age and older, pending the initial approval of the vaccine.

“The data we’ve seen to date suggest a third dose of our vaccine elicits antibody levels that significantly exceed those seen after the 2-dose primary schedule,” said Albert Bourla, Chairman and CEO, Pfizer. “We are pleased to submit these data to the FDA as we continue working together to address the evolving challenges of this pandemic.”

The Pfizer-BioNTech COVID-19 vaccine, BNT162b2, is currently authorized for use under an Emergency Use Authorization for active immunization to prevent COVID-19 in individuals 12 years of age and older. The vaccine is administered intramuscularly as a 2-dose series (0.3mL each) spaced 21 days apart.


Pfizer and BioNTech announce submission of initial data to U.S. FDA to support booster dose of COVID-19 vaccine. News release. Pfizer Inc and BioNTech SE. Accessed August 16, 2021.