Britain does not yet know how strong its defences against future waves of coronavirus will be, despite the success of the vaccine rollout, Prime Minister Boris Johnson said on Monday.
"The vaccine rollout has been very impressive, and thanks to everybody who's been involved in it, but what we don't know is exactly how strong our fortifications now are, how robust our defences are against another wave," Johnson told a news conference.
(Reporting by Alistair Smout, writing by William James)
