– The advisors overwhelmingly support authorization, but rejected the offer of full approval
By Molly Walker
An FDA advisory panel recommended emergency use authorization (EUA) for a booster dose of the Pfizer/BioNTech COVID-19 (Commonwealth) vaccine for people 65 years of age and older, and those considered to be at high risk of severe COVID-19.
On Friday, the FDA’s Vaccines and Related Biologics Advisory Committee (VRBPAC) voted 18-0 against the known and potential benefits of a booster dose outweighing the known and potential risks for older adults and for people 16 and older at high risk of severe illness. The committee also agreed that healthcare workers and others at high risk of occupational exposure should be included in the EUA, which Peter Marks, MD, PhD, of the FDA’s Center for Biologics Evaluation and Research (CBER), said could include frontline workers such as teachers and certain infrastructure workers.
However, the committee did not recommend full approval of a booster dose for all people aged 16 and over, with a vote of 2 to 16, and cited mainly the lack of safety data for the general population, including the risk of myocarditis in younger men.
Not only that, but VRBPAC did not believe the manufacturer Pfizer's argument about "decreased vaccine efficacy" as a major factor in transmission, since CDC staff noted that transmission in the US was driven primarily by the unvaccinated population.
“I have serious concerns about extrapolating from the much larger population to 16- and 17-year-olds,” said Archana Chatterjee, MD, PhD, of Rosalind Franklin University in North Chicago. “There is no data on this population, and the security database presented was far too small.”
Pfizer submitted safety and immunogenicity data from a cohort of approximately 300 adults aged 18 and older from Phase I/II/III trials who received booster doses, including only 12 adults aged 65 and older. This was the only data the committee was allowed to consider in its first voting question on approval, although Marks said committee members could consider the “totality of the evidence.”
The committee members were most surprised by the real-world data from Israel, published this week in the New England Journal of Medicine ( NEJM ), which showed a benefit for a booster dose for adults aged 60 and over.
“The safety data we have reflects people in their 60s,” said Eric Rubin, MD, PhD, of the Harvard T.H. Chan School of Public Health in Boston, and editor-in-chief of the NEJM . “That’s quite different from ‘people should get a third dose,’” which he described as “closer to being written as a mandate that everyone should get it.”
Mark Sawyer, MD, of the University of California, San Diego, was one of only two "yes" votes on the first question, and said he thought approval for the general population was the "fastest and most efficient way for providers" to target certain high-risk populations that needed booster doses.
Sawyer also voted yes to the US question.
“I think this is a really amazing vote” for older adults and health care workers, who were vaccinated earlier and needed more protection, said Amanda Cohn, MD, of the CDC. She also said she was hopeful that once more data became available, they would meet again to vote on a third dose for the general population.
Marks appeared inclined to push VRBPAC members to vote for approval, and took the time to display a slide from the CDC's Advisory Committee on Immunization Practices (ACIP) showing that half of the currently recommended vaccines require an additional dose 6 months after the primary one.
He added that the idea of preventing severe illness and hospitalization was only one part of a vaccine's job, as they are "indicated for various disease severities," including preventing the continued spread of COVID-19 to vulnerable populations, such as children and young people, who also need to be vaccinated.
Ultimately, the committee was reluctant to approve the vaccine for a number of reasons. In addition to safety data, committee members said they wanted to see vaccines based on the circulating variant, longer studies between primary trials, and even a longer follow-up period after the booster dose to determine the durability of immunity.
CDC staff also noted that they are currently evaluating data on the one million people who received a third dose of the vaccine and expect it to be available soon.
From: https://www.medpagetoday.com/infectiousdisease/covid19vaccine/94579