Four preliminary laboratory studies released over the weekend found that antibodies from previous infections and vaccinations appear capable of neutralizing the variant, known as BA.2.86.

"It is reassuring," says Dr. Dan Barouch, who conducted one of the studies at the Beth Israel Deaconess Medical Center in Boston.

When it was first spotted, BA.2.86 set off alarm bells. It contains more than 30 mutations on the spike protein the virus uses to infect cells. That's a level of mutation on par with the original Omicron variant, which caused a massive surge.

The concern was BA.2.86, while still rare, could sneak around the immunity people had built up and cause another huge, deadly wave.