A new super-variant could be created if Omicron and Delta infect someone at the same time, warned Moderna chief physician Paul Burton.
According to an article in the online edition of the Daily Mail, infections from Covid usually involve only one mutant strain, but in extremely rare cases two can "hit" at the same time.
Also, if they infect the same cell, they may be able to exchange DNA and combine to create a new version of the virus.
Paul Burton warned that the large number of Delta and Omicron cases currently circulating in Britain make this more likely.
Speaking to members of the Science and Technology Committee, he said it was "definitely" possible to exchange genes and activate an even more dangerous variant.
Researchers have warned that these events, scientifically termed "recombination events", are possible but require very specific conditions.
Only three Covid strains created from genes that exchanged genes have been recorded, with the virus relying mainly on random mutations to make more variants.
However, a new variant was not activated through this method during the two months that Delta dominated Alpha.
The Omicron variant has already dominated London just two weeks after it was spotted in the country and experts estimate that it will be the dominant strain until the New Year.
Dr. Burton stressed that the release of the two variants together increases the risk of exchanging genes and creating a new variant.
"It simply came to our notice then. There have been some studies from South Africa that say that humans - and certainly immunocompromised humans - can hide both viruses. "This would be possible here, especially given the number of infections we have seen."
Asked if this could lead to a more dangerous variant, he said he "certainly could".
Source: dailymail.co.uk/ΕΡΤ