New, highly mutated COVID variants ‘Pirola’ BA.2.86 and JN.1 may cause more severe disease, new studies suggest

People wearing masks amidst rising concerns about the new, highly mutated COVID variant JN.1, as seen in Kolkata, India, on Dec. 27, 2023. BA.2.86, a close ancestor of JN.1, may cause more severe disease, according to two new studies published Monday. (Credit: Debarchan Chatterjee/NurPhoto via Getty Images)

Highly mutated COVID variant BA.2.86—close ancestor of globally dominant “Pirola” JN.1—may lead to more severe disease than other Omicron variants, according to two new studies published Monday in the journal Cell.

In one study, researchers from Ohio State University performed a variety of experiments using a BA.2.86 pseudovirus—a lab-created version that isn’t infectious. They found that BA.2.86 can fuse to human cells more efficiently and infect cells that line the lower lung—traits that may make it more similar to initial, pre-Omicron strains that were more deadly.