Pfizer, BioNTech Initiate Rolling FDA Application Submission for Booster Dose of COVID-19 Vaccine

Pfizer and BioNTech have initiated rolling submission of the Biologics License Application (BLA) to the FDA for approval of a COVID-19 vaccine booster dose in individuals 16 years of age and older, according to a press release.¹

The application is supported by new phase 3 data showing that a third dose of the vaccine, marketed under the name Comirnaty, induces significant neutralizing antibody titers with a favorable safety and tolerability profile. According to the press release, SARS-CoV-2 neutralizing titers against the wild-type strain 1 month after the booster dose were 3.3 times higher than the titers found 1 month after the second dose.¹

These findings are from a phase 3 clinical trial with 306 participants between 18 and 55 years of age who received a third dose of the vaccine between 4.8 months and 8 months after the primary 2-dose regimen, with a median follow-up time of 2.6 months post-booster. The neutralizing titers after the third dose met a prespecified 1.5-fold non-inferiority criterion for success and were statistically superior.¹

Furthermore, 99.5% of participants had a 4-fold response after the third dose, compared to 98% after the second dose. The titers after dose 3 met the pre-specified 10% non-inferiority margin for the difference in the 4-fold seroresponse rates, according to the press release.¹

The reactogenicity profile within 7 days after the booster dose was typically mild to moderate and the most common events included injection site pain, fatigue, headache, muscle and joint pain, and chills. There was a low frequency of any severe systemic event after administration of the third dose. The frequency of reactogenicity was similar to or better than after dose 2 of the primary series, and the adverse event profile was generally consistent with other clinical data.¹

The third dose is not currently authorized for broad use in the United States, although it was authorized on August 12 for administration to individuals at least 12 years of age who have undergone solid organ transplantation, or those who are diagnosed with conditions that have equivalent levels of immunocompromise.¹

The Biden administration has announced plans to have messenger RNA (mRNA) COVID-19 vaccine boosters widely available beginning September 20, based on evidence of waning efficacy. In a press briefing on August 18, experts outlined data from New York State that show protection against hospitalization among vaccinated individuals declined from approximately 92% in May to approximately 80% at the end of July.²

“When we look at the data, we see a reduction in the protection against mild and moderate disease in all age groups, and that’s why we made this recommendation for all adults,” said US Surgeon General Vivek Murthy, MD, MBA, during the briefing.²

Pfizer and BioNTech’s application initiation also comes after the full FDA approval of the primary 2-dose series, which was granted August 23, 2021. The data supporting this approval included efficacy findings in approximately 20,000 vaccine recipients and 20,000 placebo recipients 16 years of age and older who did not have evidence of COVID-19 virus infection within a week of receiving the second dose. According to a press release, the vaccine was 91% effective in preventing COVID-19 infection.³

“The FDA’s approval of this vaccine is a milestone as we continue to battle the COVID-19 pandemic,” said Acting FDA Commissioner Janet Woodcock, MD, in the press release. “While this and other vaccines have met the FDA’s rigorous, scientific standards for emergency use authorization, as the first FDA-approved COVID-19 vaccine, the public can be very confident that this vaccine meets the high standards for safety, effectiveness, and manufacturing quality the FDA requires of an approved product.”³

REFERENCES

1. Pfizer and BioNTech Initiate Rolling Submission of Supplemental Biologics License Application to US FDA for Booster Dose of Comirnaty in Individuals 16 amd Older. News release. Pfizer; August 25, 2021. Accessed August 25, 2021. https://www.pfizer.com/news/press-release/press-release-detail/pfizer-and-biontech-initiate-rolling-submission

2. Pharmacy Times. Biden Administration Outlines Plan for COVID-19 Booster Shots Beginning September 20. August 18, 2021. Accessed August 25, 2021. https://www.pharmacytimes.com/view/biden-administration-outlines-plan-for-covid-19-booster-shots-beginning-september-20

3. Pharmacy Times. FDA Fully Approves Pfizer-BioNTech COVID-19 Vaccine. August 23, 2021. Accessed August 25, 2021. https://www.pharmacytimes.com/view/fda-fully-approves-pfizer-biontech-covid-19-vaccine