WASHINGTON: The US Food and Drug Administration (FDA) told COVID-19 vaccine developers on Tuesday (Oct 6) it wants at least two months of safety data before authorising emergency use, a requirement that would likely push any US vaccine availability past the Nov 3 presidential election.
A senior administration official confirmed the White House had approved the plan, which undercuts President Donald Trump's hopes of getting a vaccine before voters go to polls.
Trump voiced his displeasure in a Twitter post late on Tuesday: "New FDA Rules make it more difficult for them to speed up vaccines for approval before Election Day. Just another political hit job!"
The FDA released the guidance laying out more stringent recommendations for drugmakers hoping to apply for an emergency use authorisation (EUA) for their experimental vaccines.
The New York Times reported on Monday that the guidelines had been blocked by the White House. The senior administration official said there had been no holdup of the guidance, which underwent normal regulatory review.
The move is the latest effort by US officials to play down politics around the vaccine and assure public safety.
"Being open and clear about the circumstances under which the issuance of an emergency use authorisation for a COVID-19 vaccine would be appropriate and is critical to building public confidence and ensuring the use of COVID-19 vaccines once available," Dr Peter Marks, director of the FDA division responsible for approving vaccines, said in a statement.
The White House could still force authorisation of a vaccine without that additional safety data. Doing so would put it in open disagreement with the FDA and its career scientists, and add to the perception that politics was playing a role in pushing out a vaccine.
If the agency follows its own guidelines, it is unlikely to authorise a vaccine before sometime in late November. It wants two months of data from half of a trial's volunteers.
Pfizer Inc and partner BioNTech are expected to be the first to announce results from a late-stage US clinical trial.
About half the volunteers in the 44,000-subject Phase III trial had received the second dose of the two-shot vaccine by late September.
Pfizer had previously said it expected to release efficacy data as early as this month and provide FDA with safety data, including the median of two months' safety data after the second dose, on a rolling basis.
The head of the US government's Operation Warp Speed vaccine development program said on Tuesday efficacy data on one or two vaccines will be available within the next month or two, and that there should be enough supply to immunize 30 million people during November and December.
Moderna Inc appears likely to be the second company after Pfizer that will have US trial data available for an EUA review.
Pfizer Chief Executive Albert Bourla tweeted on Tuesday that the company had not discussed the FDA's standards with the White House, saying that could compromise the agency's independence.
The FDA's "public servants are known for their high integrity and scientific expertise and we have full faith in their ability to set appropriate standards for the approval of a COVID vaccine or treatment", Bourla said.
The FDA expects to hold separate meetings of its vaccine advisory committee before issuing an emergency use authorisation for any experimental shot.