"We hope that the Oxford-AstraZeneca will provide longer-term protection," Mr Soriot told the Daily Mail.

"The science so far suggests that our vaccine provides a strong T-cell response, which I hope means its effects will last longer. So it looks good, but we don't yet know for sure whether you will need a booster. Time will tell."

Scientists believe T-cells, a type of white blood cell, may provide longer-lasting immunity to Covid than antibodies. In April, a Birmingham University study found that the AstraZeneca jab appeared elicit a stronger T-cell response than either Pfizer or Moderna.

Meanwhile, data collected by Johnson & Johnson, whose vaccine is based on the same technology as the AZ jab, showed it "provides years of protection", Mr Soriot said.

It would be wild if the mRNA vaccines (which I got, and was glad to get) end up needing a booster of some other vaccine rather than vice versa.

Maybe not, but I do think we're only just starting to understand what vaccine protection looks like, and the "best" vaccine can change depending on the circumstances.

Which just means, the vaccines are good and anyone should take any vaccine they can get. And then wait and see if we need another one sometime.