The vaccines advisory committee voted late on Friday, September 17, 2021, to provide emergency authorization of Pfizer’s COVID-19 vaccine as a booster for those over the age of 65, as well as for those at high risk of developing severe disease.
The FDA’s Vaccines and Related Biological Products Advisory Committee voted 16-2 against full approval for the use of Pfizer/BioNTech’s COVID-19 vaccine, Comirnaty, in people over the age of 16. But they did vote unanimously to provide an emergency use authorization of the vaccine as a booster after six months for those over the age of 65 and those at high risk of severe COVID-19.
Committee members recognized research that showed waning immunity from the COVID vaccines over time, but they indicated there was not enough data to support a third dose in the general population. They were concerned about the safety of the third dose of the vaccine, specifically heart inflammation, and they wanted to see data specifically on this area of safety.
Materials the FDA released before the meeting included an analysis of real-world data in Israel that found a third dose of the vaccine boosted vaccine effectiveness to the level initially seen after the second dose. Investigators found that the rate of confirmed infection was lower in the booster group than in the nonbooster group by a factor of 11.3, and the rate of severe illness was 7.5 cases per 100,000 person-days.
The third dose of the Pfizer vaccine in Israel was approved on July 30, and investigators analyzed data through Aug. 31, 2021. This study was published in the New England Journal of Medicine ahead of the meeting.
FDA advisory committee members were concerned about myocarditis in younger people given the third dose. Investigators in Israeli study found that out of about 2 million booster doses, a small number of people experienced serious adverse events.
In the United States, safety surveillance reports received by FDA and CDC identified serious risks for myocarditis and pericarditis following administration of the first two doses of the vaccine, with higher rates seen in men under the age of 40 with the highest rates among male adolescents 16 and 17 years of age, according to a briefing document. An FDA analysis of the Optum database estimated an excess risk approaching 200 cases per million vaccinated males 16 and 17 years of age, but information was not available on long-term outcomes related to myocarditis.
When polled, all committee members agreed when polled to extending the EUA booster to those at risk for occupational exposure, including health care workers.
In August, the FDA expanded the EUA for a booster of the Pfizer vaccine to those at least 12 years of age who have undergone an organ transplant, or who have conditions that lead to a similar level of level of compromised immune system. This authorization is separate and distinct from the booster dose reviewed by the committee.