Drug companies will be expected to hit a series of milestones before they are allowed to distribute a coronavirus vaccine, a move that experts say makes it unlikely one will be approved before the US election.
The Food and Drug Administration has privately told vaccine makers they want them to comply with a set of guidelines that go beyond what the agency has said publicly, according to three people close to the discussions.
Peter Marks, director of the FDA department that oversees vaccines, had pushed for the new standards as a way to avoid politicisation of the agency, one person said. Mr Marks did not respond to a request to comment.
The guidelines, which include asking companies to wait until they have monitored trial participants for a median time of at least two months, are not yet hard-and-fast rules. But the FDA is now debating making them public in a move that would make it difficult for companies to ignore them.
Their existence was first revealed by The Washington Post.
“Companies have been told from the start they will be expected to comply with standards that go beyond what has been set out formally,” said a person briefed on the guidelines. “Now there is a discussion about whether the administration should formalise what has already been communicated privately.”
An executive familiar with the matter said the tougher guidelines would make it “more challenging” to file for approval ahead of the November election — but that vaccine makers would welcome them as they would be “really helpful” to improve public trust.
“The entire industry writ large is distraught about the fact that confidence is slipping in taking the vaccine because everybody is rushing headlong into this,” he said. “We’ve devoted incredible resources.”
Tom Inglesby, director of the Johns Hopkins Center for Health Security in Baltimore, said the new guidelines would likely mean it would take until December to get results.
“The companies were only halfway through enrolling people at the end of August,” he said. “They need time for more people to enter the trial, they need three to four weeks to get the second dose of vaccine, and they need at least two months of study after that. Vaccine trials take time. They just do.”
Donald Trump has said he expected a vaccine to be available possibly as soon as next month. The US president told a cheering crowd of supporters last weekend one would be ready “within weeks”. “We are rounding the corner on the pandemic,” he added.
Stephen Hahn, the head of the FDA, told the Financial Times last month that he was willing to consider a fast-track process to authorise a vaccine, known as an emergency use authorisation. But those familiar with the process said he has asked drug companies to hit a set of standards that go beyond what is normally requested for an EUA, including waiting until participants in phase 3 trials have gone through a median of at least two months of monitoring after receiving their last shot.
Moderna and Pfizer, with its partner BioNTech, started their trials in late July. But both companies gave two doses, meaning the clock would not have started until late August for even the first wave of participants. Moderna recruited 2,000 out of the 30,000 participants in its first week, so they will hit the two-month mark in late October. It is therefore likely to be much later for the middle group of recruits to hit that point, as the guidelines request.
Other guidelines, not previously made public, include having at least five of the infections result in severe illness in the placebo group for each trial, to prove that the vaccine protects against the most devastating developments of the disease. There should also be cases of Covid-19 in older people, who are more vulnerable and have immune systems that can be less responsive to a vaccine.
There is no set timeline for when the large phase 3 trials will have gathered enough evidence to submit a vaccine for regulatory approval. Vaccine makers have estimated that is likely to happen at some point between October and December.
The FDA had already made clear that it expected any vaccine to be at least 50 per cent effective.
The pharmaceuticals industry is worried about being dragged into politics and losing public trust in their vaccines. In an unusual statement, the chief executives of nine major vaccine manufacturers pledged earlier this month to only submit a potential Covid-19 vaccine for approval if it complied with the requirements set out by the FDA.