Kate Bingham, the former head of the UK's Covid-19 Vaccine Taskforce who secured millions of doses for the country, said scientists should know within a week whether existing shots are effective against the Omicron variant of the coronavirus.
Bingham, a venture capitalist who backed multiple vaccines at the start of the pandemic to secure early access for Britain, said she currently expected that the leading shots would still show efficacy.
"The question is do they have the same level of efficacy?" she said on Wednesday.
Bingham, who has returned to her role as managing partner at SV Health Investors, said Britain had built up the capability to quickly test existing vaccines against new variants.
"It's not something you can do overnight, but we will get data, I would have thought within a week as to whether or not the vaccines work or don't," she said.
Under Bingham's leadership, the UK taskforce ordered vaccines as they were still being trialled, securing supplies from Pfizer, AstraZeneca, Moderna and others to give Britain a head start in the rollout.
She said on Wednesday that she had backed the vaccine from French company Valneva, which differs from others by relying on an inactivated virus similar to flu vaccines, because having a varied portfolio would be useful when variants emerged.
Britain has since cancelled the order.
"The idea of having that as a potential vaccine in our portfolio, knowing it was going to come on stream later than the earlier ones, was precisely that you could deal with variants," she said.
She added that "unfortunately" the Valneva contract had been cancelled. "I wasn't part of the decision so I don't know the basis of it," she said. "But I would have thought that was a useful vaccine to have in our panoply of tools to actually address variants and future pandemic strains."
Sukhi Basra