The head of the US Food and Drug Administration (FDA) has raised the possibility that a future vaccine against the coronavirus might be given emergency approval before the end of trials designed to ensure its safety and effectiveness.
A request for such extraordinary approval would have to come from the vaccine developer, Dr Stephen Hahn told the Financial Times in an interview published on Sunday.
"If they do that before the end of phase three", which involves large-scale human testing, "we may find that appropriate".
But Dr Hahn insisted he was not acting under pressure from President Donald Trump, who has been pushing hard for a vaccine, saying one might be ready before US elections on Nov 3. "This is going to be a science, medicine, data decision," he said. "This is not going to be a political decision."
Three Western drug makers are well along with their phase three clinical trials, involving tens of thousands of participants.
The three are AstraZeneca, which is partnering with Oxford University in England; Moderna, which is collaborating with the US National Institutes of Health; and a Pfizer/BioNTech alliance.
By the nature of the trials it's difficult to predict when reliable results will emerge. Half of the participants in such trials receive an experimental vaccine, while the other half are given a placebo. Under normal procedures, test administrators must waitprobably for monthsto see whether there is a statistically significant difference in the infection rate of both groups.
As the world desperately awaits an effective vaccine against the deadly virus, China and Russia have already approved vaccines without waiting for the conclusion of trialsdrawing criticism from public health officials in other countries, including the US.
Dr Hahn said an emergency authorisation would not necessarily cover everyoneit might be granted for specific, high-risk groups.
The FDA chief has faced mounting criticism from the medical community that he has given in to political pressure from the Trump administration.
In March, the FDA gave emergency authorisation for the use of hydroxychloroquine to treat Covid-19 after Mr Trump repeatedly praised its use; the authorisation was withdrawn in June after serious side effects emerged. More recently, Dr Hahn gave a far too optimistic appraisal, during a news conference with Mr Trump, of the effectiveness of convalescent plasma against the virus. He said it could save 35 out of 100 patients; the more likely number, experts said, is five in 100.
AGENCE FRANCE-PRESSE