Dr Paul Burton, the Moderna vaccine maker's chief medical officer, warned the high numbers of Delta and Omicron cases currently circulating in Britain made this more likely.

He told MPs on the Science and Technology Committee that it was 'certainly' possible they could swap genes and trigger an even more dangerous variant, reports Daily Mail.

Burton told the Commons that having the two variants circulating together raised the risk of them swapping genes and making a new variant.

He was quoted as saying by Daily Mail: "There's certainly data, there have been some papers published again from South Africa earlier from the pandemic when people — and certainly immunocompromised people — can harbour both viruses."

"That would be possible here, particularly given the number of infections that we were seeing," he said.

Asked whether this may lead to a more dangerous variant, he said it 'certainly could'.