British regulators are also vetting a vaccine developed by AstraZeneca, a British-Swedish company, and the University of Oxford that is cheaper and easier to store than Pfizer’s. Much of the world could rely on it, but its regulatory path forward in the United States is unclear after scientists and industry analysts questioned promising early results.
The chemistry underlying Pfizer’s vaccine had never before produced an approved shot, though the same class of vaccines has long been tested for other uses. In order to coax cells to make a viral protein, called spike, and elicit an immune response, the vaccine delivers genetic instructions, known as messenger RNA, encased in tiny fat globules.
BioNTech made a prophetic bet on the technology and joined forces with Pfizer, one of the world’s largest drug companies; they ended up delivering stunning results, on a timeline that was unheard-of before this year.
“The emergency use authorization in the U.K. will mark the first time citizens outside of the trials will have the opportunity to be immunized against Covid-19,” said Dr. Ugur Sahin, the chief executive and co-founder of BioNTech.
The U.S. Food and Drug Administration plans to decide on emergency authorization for the Pfizer vaccine shortly after a meeting of an advisory panel on Dec. 10. American officials have said vaccinations could begin within 24 hours after approval.
Another American company, Moderna, whose messenger RNA vaccine proved extraordinarily effective in large trials, said it would also apply to the F.D.A. for emergency authorization. If granted, it could go into use as early as Dec. 21, the company has said.
Britain’s power to approve vaccines before the European Union, which has its own drug regulator, applies for now only on an emergency basis. But it will become permanent after Britain consummates its split from the bloc on Dec. 31, making the speed of the Pfizer approval an early sign in the eyes of the government of the flexibility it will have once the country fully untethers itself from the rest of Europe.