FDA to require vaccine to prevent covid-19 or decrease severity in 50 percent of recipients
The Food and Drug Administration said Tuesday that to win regulatory approval, any covid-19 vaccine will have to prevent the disease or decrease its severity in at least 50 percent of the people who receive it.

The agency also said it would require drug companies to monitor the vaccine’s performance after approval for any emerging safety problems.

The agency issued guidance to vaccine developers in conjunction with testimony by FDA Commissioner Stephen Hahn and other health officials before the Senate Health, Education, Labor and Pensions Committee on how schools and businesses can safely reopen amid the pandemic.

The standards spelled out apply to full approvals. But many expect a vaccine initially will be made available under a much lower standard, through what is called an emergency use authorization. The guidance said any decision on an emergency authorization would be made “on a case-by-case basis considering the target population, the characteristics of the product” and the available evidence, including clinical trial data on safety and effectiveness.

The Trump administration is eager to dispel concerns the FDA may be under political pressure to approve a vaccine that has not been completely vetted for safety and efficacy. The agency was criticized for giving emergency authorization to the malaria drug hydroxychloroquine. That authorization was recently revoked after trials showed it was ineffective and the FDA got reports of heart problems caused by the drug.

Biotechnology analysts at the Jefferies financial-services company said Tuesday they expected the FDA to grant emergency authorization for a vaccine, given the administration’s stated goals of having a vaccine by later this year or early next.

Hahn, in his opening statement, said the public should be assured that the agency has “not lost sight” of the importance of making independent regulatory decisions based on sound science and data.