The scientist behind the AstraZeneca Covid vaccine has said giving booster jabs to everyone is unnecessary, and instead calls for doses to be sent to countries in need.
Professor Dame Sarah Gilbert said the decision over boosters needed to be looked at carefully.
The Joint Committee on Vaccination and Immunisation (JCVI) recently said a third dose should be offered to people with severely weakened immune systems, but has not decided if boosters are needed more widely and who would be eligible.
Interim advice issued by the JCVI in July suggested more than 30 million people should receive a third dose, with the UK vaccine advisory body due to give its final advice on boosters soon.
The UK medicines regulator (MHRA) has approved the use of Pfizer and AstraZeneca as Covid booster vaccines.
Health Secretary Sajid Javid said on Thursday (9 September) he was awaiting "final advice" from the JCVI, but was "confident" a booster programme would start later this month.
'I don't think we need to boost everybody'
Professor Dame Sarah Gilbert told the Daily Telegraph some vulnerable groups would need boosters, but immunity was "lasting well" in the majority of cases.
She said: "We will look at each situation; the immunocompromised and elderly will receive boosters.
"But I don't think we need to boost everybody. Immunity is lasting well in the majority of people."
However, she said the UK needed to help more countries around the world with vaccine supply.
She said: "We need to get vaccines to countries where few of the population have been vaccinated so far.”
"We have to do better in this regard. The first dose has the most impact,” she added.
There are currently huge differences in the pace of Covid vaccination progress in parts of the world.
The UK government has therefore pledged to donate 100 million surplus Covid jabs to poorer countries before the middle of 2022.