BioPharma, Policy

FDA will not ‘cut corners’ in assessing Covid-19 vaccines, commish says

The agency issued a guidance for industry laying out its various recommendations for vaccine development. The announcement preceded the release of data from Pfizer and BioNTech’s Phase I/II clinical trial of their messenger RNA vaccine.

FDA Commissioner Stephen Hahn testifies March 3 about the COVID-19 coronavirus outbreak before the Senate Committee on Health, Education, Labor and Pensions

Food and Drug Administration Commissioner Stephen Hahn appeared to want to assuage growing fears that the agency could allow a vaccine against Covid-19 to reach the market prematurely as the FDA announced a new guidance to aid the vaccines’ development.

The agency said Tuesday that it would expect a Covid-19 vaccine to prevent the disease or decrease its severity in at least 50% of people who are vaccinated in order to meet the bar for approval. In addition, the agency said that any potential emergency use authorization would be assessed on a case-by-case basis and take into consideration factors like target population, product characteristics and scientific evidence.

The 24-page guidance lays out the FDA’s recommendations for things like chemistry, manufacturing and controls, collection of preclinical data and also conduct and design of clinical trials. For example, later-phase trials should be randomized, double-blinded and placebo-controlled, the agency said, while follow-up of study participants for Covid-19 outcomes should continue ideally for at least one to two years to assess duration of protection and potential for vaccine-associated enhanced respiratory disease.

“We recognize the urgent need to develop a safe and effective vaccine to prevent Covid-19 and continue to work collaboratively with industry, researchers, as well as federal, domestic and international partners to accelerate these efforts,” Hahn said in a statement. “While the FDA is committed to expediting this work, we will not cut corners in our decisions and are making clear through this guidance what data should be submitted to meet our regulatory standards.”

The guidance comes as several companies have announced preliminary data from clinical trials of vaccines, showing that study participants have developed neutralizing antibodies against the SARS-CoV-2 virus. Most recently, Pfizer and BioNTech said Wednesday that their messenger RNA-based vaccine candidate, BNT162b1, resulted in participants developing antibodies at concentrations many times higher than those of Covid-19 patients who had recovered. However, production of antibodies in response to vaccination does not mean somebody is immune to the virus, and if they are, it remains unclear how long that immunity will last. That uncertainty has led to concerns that the FDA could come under pressure to issue an emergency use authorization for a vaccine prematurely and for political rather than scientific reasons, as it was accused of doing when it issued the EUA – since rescinded – for the malaria drugs hydroxychloroquine and chloroquine.

However, Hahn seemed to downplay that risk.

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“We have not lost sight of our responsibility to the American people to maintain our regulatory independence and ensure our decisions related to all medical products, including Covid-19 vaccines, are based on science and the available data,” he said in a statement. “This is a commitment that the American public can have confidence in and one I will continue to uphold.”

Photo: Saul Loeb, AFP, via Getty Images