Mr Soriot said: “What remains and is very important is this T-cell response. 

“And as soon as the virus attacks you, they wake up and they come to the rescue and the defend you and but it takes them a little while so you may be infected, but then they come to the rescue and you don’t get hospitalised and it’s really interesting when you look at the UK, the there was a big peak of infections, but not so many hospitalisations relative to Europe. 

“In the UK, this vaccine was used to vaccinate older people. Whereas in Europe initially people thought the vaccine doesn’t work in older people.”

Emmanuel Macron and German Chancellor Angela Merkel both publicly suggested the AstraZeneca jab was of no use to older people, with the French President calling it “quasi-ineffective”.

Asked if that was a mistake by Europe, Mr Soriot said: “I’m not saying there was any mistake done by anybody. I’m just saying that there’s a lot of data that still need to be made available that we don’t have.”

And pressed on the BBC if there could be a link between hospitalisation rates and the fact that AstraZeneca wasn’t used in older people meaning the T-cell response isn’t there, he said: What I’m saying is T-cells do matters, and in particular as it relates to the durability of the response, especially in older people, and this vaccine has been shown to stimulate T-cells to a higher degree in older people. 

“And so we haven’t seen many hospitalisations in the UK, a lot of infections, for sure, everybody talking about those. 

“But what matters is are you severely ill or not are you hospitalised or not? And we haven’t seen so many of these hospitalisations.

“There’s no proof of anything. We don’t know [if because AstraZeneca was used among older people in the UK instead of Pfizer or Moderna] but we need more data to analyse this and get the answer.”

Germany is debating the possibility of introducing a general vaccine mandate next year amid warnings that it is facing a fifth wave of Covid cases.