Omicron subvariant may be more infectious and cause more severe COVID symptoms, study warns

TOKYO, Japan — An emerging Omicron subvariant, BA.2, may become an even greater threat than its predecessor as the COVID-19 pandemic drags on.

BA.1 is what scientists call the Omicron variant. According to a pre-print study conducted by Japanese researchers, this new offshoot of Omicron made hamsters sicker and caused more lung damage and weight loss than BA.1.

“Our multiscale investigations suggest that the risk of BA.2 for global health is potentially higher than that of BA.1,” the researchers write in the pre-print server bioRxiv.

The new experiment, which compared infections among animals with either BA.1 or BA.2, found similar results among mice as well. Both strains appear to evade the protection coming from COVID-19 vaccinations. However, researchers found that monoclonal antibody therapies had less success at treating animals with BA.2.

“Infection experiments using hamsters show that BA.2 is more pathogenic than BA.1,” the study authors add.

The report finds BA.2 is also “almost completely resistant” to two specific monoclonal antibody therapies — casirivimab and imdevimab. Moreover, BA.2 is up to 35 times more resistant to the COVID treatment sotrovimab than the original COVID strain, B.1.1.

“In summary, our data suggest the possibility that BA.2 would be the most concerned variant to global health,” the researchers continue. “Currently, both BA.2 and BA.1 are recognized together as Omicron and these are almost undistinguishable. Based on our findings, we propose that BA.2 should be recognized as a unique variant of concern, and this SARS-CoV-2 variant should be monitored in depth.”