“It’s crazy infectious,” said Paula Cannon, PhD, a virologist at the University of Southern California, Los Angeles. “All the things that have protected you for the past couple of years, I don’t think are going to protect you against this new crop of variants.”
XBB.1.5 is spreading quickly in the United States. It accounted for 27.6% of cases in the country in the week ending on Jan. 7, up from about 1% of cases at one point in December, according to the Centers for Disease Control and Prevention. It’s especially prevalent in the Northeast, now accounting for more than 70% of the cases in that region.
It’s spreading across the globe, too. Maria Van Kerkhove, PhD, technical lead of the World Health Organization, has called XBB.1.5 is “the most transmissible subvariant that has been detected yet.”
Ashish Jha, MD, the White House COVID-19 response coordinator, tweeted a few days ago that the spread of XBB.1.5 is “stunning” but cautioned that it’s unclear if the symptoms of infection will be more severe than for previous variants.
“Whether we’ll have an XBB.1.5 wave (and if yes, how big) will depend on many factors including immunity of the population, people’s actions, etc.,” he tweeted.
He urged people to get up to date on their boosters, wear a snug-fitting mask, and avoid crowded indoor spaces. He noted that people who haven’t been infected recently or haven’t gotten the bivalent booster likely have little protection against infection.
The symptoms for XBB.1.5 appear to be the same as for other versions of COVID-19. However, it’s less common for people infected with XBB.1.5 to report losing their sense of taste and smell, USA Today reported.
A version of this article first appeared on WebMD.com.