FDA Panel Votes No On General Public COVID-19 Booster Dose: What That Means

The FDA's vaccine advisory committee has voted against a generally available third Pfizer COVID-19 booster, though left alternative routes open for other high-risk individuals. The panel, comprised of independent public health and scientific experts, pushed back at suggestions that sufficient data of vaccine safety had been gathered.

The Vaccines and Related Biological Products Advisory Committee is a non-binding committee, and the FDA is not obliged to follow its recommendation, or the final vote. The Biden Administration said in mid-August 2021 that it planned to open third booster shots to the general public in September, though only with FDA and CDC approval first.

After several hours of presentations, including data from Pfizer studies of the newly-approved and branded Comirnaty vaccine, along with data gathered from Israel and the UK, the panel came together for a vote.

"Do the safety and effectiveness data from clinical trial C4591001 support approval of a Comirnaty booster dose administered at least 6 months after completion of the primary series for use in individuals 16 years of age and older?" the panel were asked. 16 out of 18 people voted no. An error inadvertently saw a third "yes" vote added, which was later corrected.

Among the concerns voiced were whether sufficient data had been presented that vaccine efficacy could be improved by a third booster for younger populations in particular. Older, immunocompromised populations – and potentially those with a BMI of over 35 – were a different matter, however.

Several of those on the panel suggested that more targeted boosters would be more appropriate, rather than universally expanding them to a broader population. The FDA and CDC has already taken some steps there, recommending in August that some immunocompromised individuals should have a third shot of the Pfizer or Moderna vaccines. Those groups include those who have received organ or stem cell transplants, for example, who are actively being treated for cancer, or who take medications which reduce their immune system response.

The White House's plan to expand booster shots far more broadly, though, has been controversial. In addition to the FDA's panel today, the CDC has scheduled a two day meeting next week, where it plans to explore how a booster shot could be distributed.

The CDC reiterated during the post-vote discussion that it was clear that the unvaccinated are driving COVID-19 transmission in the US. Participants were also asked what sort of age they would see as appropriate for boosters to be offered to, beyond the current group. Generally, third shots for those aged 60-65 was agreed upon.

Another suggestion was that broadening the language for eligibility could be key. For example, the offer of a third, booster dose could be made to those "at greater risk" of disease, an expansion that would accommodate those working in healthcare settings or similar.

Further votes are set to be undertaken on a narrower implementation of booster doses. The suggested question would focus on whether the evidence supports a booster shot administered at least six months after the primary series of shots, for individuals aged 65 years and older, "and those judged to be at high risk of complications due to occupational exposure or underlying disease."

Update: In a second vote, the panel was asked a question about a narrower implementation of booster doses:

Based on the totality of scientific evidence available, including the safety and effectiveness data from clinical trial C4591001, do the known and potential benefits outweigh the known and potential risks of a Pfizer-BioNTech COVID-19 vaccine booster dose administered at least 6 months after completion of the primary series for use in:

Individuals 65 years of age and older, and

Individuals at high risk of severe COVID-19

All 18 members of the panel voted yes on the vote.

In a question to the committee, the panel voted on whether those at high risk for occupational exposure should be included in the booster program. That would include healthcare workers, frontline workers such as teachers, and others such as infrastructure workers. All 18 members of the panel polled yes to the question.

This is a developing story...