FDA Appears Ready to Ask Pfizer-BioNTech for More Studies on its COVID-19 Booster Shot Friday — Days Before Biden Wants to Begin Distribution

The FDA has indicated that it will be asking Pfizer-BioNTech to perform more studies on the COVID-19 vaccine Comirnaty’s booster shot before approving the companies’ supplemental biologics license application (BLA).

The FDA’s view was contained in briefing materials for Friday’s public meeting of the FDA’s expert panel on vaccines to discuss Comirnaty’s booster — just days before the Biden administration said it would like to begin administering COVID-19 booster shots to the general public on Sept. 20.

Pfizer-BioNTech’s BLA is primarily based on observational studies, particularly one conducted in Israel, and the FDA said that observational studies may not be enough.

“It should be recognized that while observational studies can enable understanding of real-world effectiveness, there are known and unknown biases that can affect their reliability,” wrote FDA, adding that “some studies may be more reliable than others.” FDA also said that U.S.-based studies “may most accurately represent vaccine effectiveness in the US population.”

“A determination of effectiveness of a booster dose should be supported by conducting clinical immunogenicity studies,” the FDA said in its briefing document.

Pfizer-BioNTech argued in their briefing document for the expert panel that the results of a 306-person sub-study of its booster was successful, and that data from a recently initiated booster vaccination program “in the entire eligible population of Israel indicate that, in the face of waning immunity and in the period when Delta is the dominant variant, a booster dose … has a reactogenicity profile similar to that seen after receipt of the second primary series dose and restores high levels of protection against COVID-19 outcomes,” that is back to approximately 95 percent protection.

The Biden administration’s Aug. 24 announcement about beginning to give boosters on Sept. 20 (DID, Aug. 24) reportedly rocked the FDA, which is also currently under intense pressure to approve the vaccine for children under age 12.

Earlier this month, Acting FDA Commissioner Janet Woodcock and Centers for Disease Control and Prevention (CDC) Director Rochelle Walensky told the White House that they might need more time to review the data and may initially only recommend boosters of the Pfizer vaccine – and only for some at-risk populations (DID, Sept. 7).

The FDA has received full data on the Pfizer-BioNTech and the Moderna vaccine boosters and is awaiting data from Johnson & Johnson on a booster for its single-dose vaccine.

The Biden administration has said multiple times that it will abide by the science-based decisions of the regulatory authorities.

This week, Center for Biologics Evaluation and Research (CBER) Director Peter Marks said COVID-19 vaccine booster shots may be necessary to sustain waning immunity. Marks said he respectfully disagrees with two outgoing FDA vaccine officials as well as World Health Organization vaccine experts who argued in The Lancet this week that providing widespread boosters isn’t necessary right now (DID, Sept. 14).

The two FDA officials who were lead authors of The Lancet piece, Marion Gruber and Phil Krause, argued that it would be better to ensure that unvaccinated people get inoculated while the evidence to support boosters is still being gathered.

On Wednesday, the FDA posted a detailed announcement for its Sept. 17 open session meeting to discuss the Pfizer-BioNTech booster shot, explaining how the public can listen in.

In a Sept. 2 news briefing, Anthony Fauci, Biden’s chief medical adviser and the director of the National Institutes of Health’s National Institute of Allergy and Infectious Diseases, spoke in favor of boosters and cited the detailed Israeli data on their efficacy.

“There’s no doubt, from the dramatic data from the Israeli study, that the boosts that are being done there and contemplated here support very strongly the rationale for such an approach,” he said.

According to the CDC, 94.6 million people in the U.S. have been fully vaccinated with the Pfizer-BioNTech vaccine, 65.8 million with Moderna’s vaccine and 14.2 million with the single-dose J&J vaccine.

In Europe, there’s not as much pressure for regulators to approve a booster. The European Centre for Disease Prevention and Control has said there is no immediate need to give booster shots to the general population.

Read the briefing documents from the FDA and Pfizer here: www.fdanews.com/VRBPAC-091721-MeetingBriefing.pdf. — Suz Redfearn