British health authorities have identified a case of the so-called “deltacron” Covid variant in a patient – but experts say it is unlikely to be of concern.

The recombinant – where two different variants merge together in a person – was named by the UK Health Security Agency (UKHSA) in its weekly “variants in monitoring” list. This is a designation below “variant of concern” and “variant under investigation”.

Recombinants are uncommon but not an unheard of phenomena in virology, and scientists had previously warned that, with high levels of both delta and omicron in circulation, it was likely such an event would happen.

The exact number of deltacron cases is unknown, which is likely to be due to there being extremely few, and the UKHSA said it was only listed on the weekly variant breakdown because “we monitor everything as a matter of course”.

‘It doesn’t fill me with dread’

Paul Hunter, professor of medicine at the University of East Anglia, told MailOnline: “At the moment I’m not overly worried. If both delta and omicron are falling then, in theory, this should struggle to take off. It doesn’t fill me with dread.”

Three other Covid recombinants have been reported globally since the pandemic began, but none gained a foothold in the population and soon fizzled out.

Reports of “deltacron” emerged in January after a Cypriot lab claimed it had identified the recombinant. However, independent experts reviewed the genetic code of this instance and concluded it was far more likely to be the result of lab contamination.

The case spotted by the UKHSA is genuine but unlikely to be of any more concern.