While Matt Hancock, who resigned over the weekend as Health Secretary, said last week that people may be given a flu jab at the same time as a booster.
Although the Oxford University announced its vaccine could be used as a third-dose booster following trials, Professor Sir Andrew Pollard, director of the group, said: “There’s no indication today that we need boosters.”
He added real-world data from Public Health England had already shown that two doses offered good protection against hospital admission and death from the Alpha Kent variant and the Delta variant first identified in India.
With two doses currently preventing more than 90 per cent of hospital admissions with Covid, he said it is “difficult to say” whether a third dose could add a few more percent.
He added: “Boosters are much more about if protection gets lost over time – and we don’t know that – but if it does, could you boost? And the answer to that from these data is yes, you could.
“There’s no indication today that we need boosters, and it is something where we need to keep looking at the data and make decisions as the months go by, about whether that protection that we have is lost.”
Prof Pollard also mentioned that experts will “expect to see immunity start to wane over time because that does happen” but it will not go back “down to zero”.
His comments came as the university’s preprint study, which has yet to be peer-reviewed, was released.
It found giving people a third dose more than six months after their second led to a substantial rise in antibodies and increased the body’s T-cell ability to fight coronavirus, including its variants.
The study also found that a longer delay of up to 45 weeks between the first and second dose of the Oxford/AstraZeneca vaccine leads to enhanced immune response.
The experts said this is an important finding for countries with limited vaccine supply.
Teresa Lambe, associate professor at the Jenner Institute at Oxford, said that, regarding antibody responses with a third dose, “We were able to push them up to a level that we saw at the peak of the response after the second dose”.
She added: “This is very encouraging because we’ve already demonstrated that two doses of (the vaccine) is both efficacious and effective in the real world.”