24 Dec 2020, CNN

Michael Worobey, a biologist at the University of Arizona, has seen more than 100,000 different strains of the virus that causes Covid-19. But when he saw the new variant from the UK, he noticed something different.

"This is the first variant I've seen during the whole pandemic where I took a step back and said: 'Whoa,' " he remembers. Health officials have downplayed the possibility that the coronavirus vaccines won't work against the UK strain, but Worobey and other scientists thinks it's a possibility -- and it's just a possibility -- that this new variant might, to a small extent, outsmart the vaccines.