New research indicated the vaccine gave little protection against mild infections in young people of the so-called South African variant, though it did better against more severe infections.
The study of the South African variant, at the Witwatersrand and Oxford universities, showed the risk of catching a mild or moderate bout of Covid-19 was just 22% lower among those taking the vaccine than in people taking a placebo.
Professor Shabir Madhi, lead investigator on the AstraZeneca trial told the BBC it would still prevent serious illness or death especially as introduced severe disease by 89%,
“There is no evidence that this vaccine is not effective in preventing hospitalisation and severe illness and death, which ultimately is what we’re seeking with these vaccines today,” Edward Argar, junior health minister, told Sky.
Pfizer’s vaccine though is also thought to effective against some of the new variants.
So far, the UK has given more than 12mln Britons a dose of one or other of these two vaccines, but over the weekend ministers said booster shots might be needed to deal with the virus as it evolves.
“It would be just be normal in a sense as we did with the flu vaccine to update it to catch anything the virus is trying to do to keep ahead of it,” Argar said.
So far, only 147 people in the UK has registered positive for the South African but it is much more contagious than earlier forms and the fear is that actual infections might be much higher.