Can Omicron+Delta recombinant virus cause severe COVID infections? WHO explains

With both Omicron and Delta COVID variants spreading rapidly, recombinants were expected, World Health Organisation (WHO) stated after first solid evidence of a combination virus (Omicron and Delta) was detected. WHO officials also asserted that “when we allow the virus to circulate at an intense level it continues to evolve and more variants are expected.” Earlier this week, another recombinant COVID strain was also detected from Israel that combined Omicron BA.1 and BA.2. 

What WHO said on Omicron Delta recombinant virus?

Regarding Omicron and Delta recombinant, WHO's Maria Van Kerkhove said on Twitter, This is to be expected, especially with the intense circulation of omicron and delta. She further notified that WHO is tracking and discussing.

“Currently, no changes are being observed in its severity and transmissibility, but several studies are underway on the topic. At this stage, testing and sequencing remain critical,” she pointed out.

Unfortunately, we do expect to see recombinants because that's what viruses do - they change over time. WHO is aware of this and this is something that is in our radar. 

What is Delta + Omicron recombinant virus?

It is a hybrid version of the coronavirus that combine genes from the Delta and Omicron variants. Philippe Colson of IHU Mediterranee Infection in Marseille, France, who is the lead author for the study, noted that genetic recombinations of coronaviruses have been known to happen when two variants infect the same host cells.

"During the SARS-CoV-2 pandemic, two or more variants have co-circulated during same periods of time and in same geographical areas... This created opportunities for recombination between these two variants."

Can the virus cause severe infections?

So far, 17 confirmed cases of the recombinant virus have been detected so far in the US and Europe.Because there have been so few confirmed cases, it is too soon to know whether Deltacron infections will be very transmissible or cause severe disease.