While there is no evidence so far that XBB.1.5 is more virulent than its predecessors, a recent swirl of misinformation linking the rise of new variants to vaccination has cast a spotlight on this latest strain and raised concern among some health experts that it could further limit booster uptake.
“XBB did not evolve because people were vaccinated,” said Vaughn Cooper, a professor of evolutionary biology at the University of Pittsburgh. “The way it evolved, let’s be straight, is because people were infected by multiple viruses at the same time.”
Since the omicron variant ignited an explosion of cases last winter, it spawned a host of descendants that are even more adept at slipping past antibodies and caused most infections in the United States. The XBB line emerged as a result of two other omicron subvariants swapping parts.
