A new COVID-19 variant, HV.1, is now dominant in the U.S., accounting for more than 25% of cases, according to the latest CDC data.
For the week ending Oct. 28, the omicron subvariant made up 25.2% of cases, followed by EG.5. Both are descendants of the XBB omicron variant.
Four things to know:
- Experts believe HV.1 may be slightly better at evading prior immunity. "I would expect that it might be a slight increase in transmissibility or immune escape, which is why it appears to be dominating," Dan Barouch, MD, PhD, director of the center for virology and vaccine research at Beth Israel Deaconess Medical Center in Boston, told NBC News. "Does it change any booster recommendations so far? Probably not."
- The new COVID-19 shots were designed to target XBB.1.5. Given HV.1 is also an XBB relative, the new shots are believed to offer strong protection against the new dominant strain. An infectious disease specialist at New Haven, Conn.-based Yale Medicine, Scott Roberts, MD, told NBC that while the vaccine may not be a "perfect match," it's still a "good match" since they're all from the same variant family.
- While new shots are expected to offer protection against circulating strains, less than 4% of the U.S. population has so far received them since mid-September. Across the country, there have been numerous reports about supply issues and difficulty accessing the new shots. Vaccine hesitancy remains another issue, experts say.
- HV.1 has grown from about 4% of cases at the start of September to the end of October. It's most prevalent in HHS region 3, which includes Delaware, Maryland, Pennsylvania, Virginia, West Virginia and the District of Columbia.