COVID-19 Vaccine Manufacturers Submit Appeals to FDA for Additional Dose

The makers behind two of the largest COVID-19 vaccines, Pfizer, BioNTech, and Moderna, are seeking FDA approval for a fourth dose of their respective COVID-19 vaccines. Pfizer and BioNTech submitted an appeal to amend their Emergency Use Authorization (EUA) on March 15, 2022, while Moderna submitted one on March 17.

Pfizer and BioNTech’s application is for a booster dose for adults 65 and older who have received an initial booster of any of the authorized or approved COVID-19 vaccines. An analysis of Israeli Ministry of Health records found that confirmed infections were two times lower and rate of severe illness were four times lower among individuals who received an additional booster dose of the Pfizer-BioNTech COVID-19 vaccine administered at least four months after an initial booster dose, relative to those who received only one booster dose.

Additionally, Pfizer cited results from an ongoing open-label, non-randomized clinical trial in healthcare workers 18 and older who had been vaccinated with three doses of the Pfizer-BioNTech vaccine in their submission. Among the 154 (out of 700) participants who received a fourth dose, neutralizing antibody titers increased approximately seven-fold to eight-fold at two and three weeks after the additional booster (fourth) dose compared to five months after the initial booster (third) dose. Additionally, an eight-fold and ten-fold increase in neutralizing antibody titers against the Omicron variant (at one and two weeks after the additional booster dose respectively) were seen compared to five months after the initial booster.

Moderna applied for an amendment to its EUA that would allow for a fourth dose of its COVID-19 vaccine in adults 18 and older who have received an initial booster of any of the authorized or approved COVID-19 vaccines. Moderna’s submission is based in part on recently published data from the US and Israel.

Separately, FDA announced that it would hold a virtual meeting of its Vaccines and Related Biological Products Advisory Committee (VRBPAC) on April 6 to discuss considerations for future COVID-19 vaccine booster doses. However, VRBPAC will not be voting or discussing any product-specific applications at this meeting. The committee will also discuss the process for selecting specific strains of the SARS-CoV-2 virus for COVID-19 vaccines to address current and emerging variants.