A New, Dominant COVID Variant Is Circulating: Here’s What We Know

A new variant of COVID-19 has become the dominating strain circulating in the United States.

Replacing EG.5, also known as Eris, and FL.1.5.1, referred to as Fornax, the HV.1 variant currently accounts for more than a quarter of reported COVID cases in the U.S. It is followed by Eris and Fornax, which contribute to 21.9% and 12% of all cases, respectively.

HV.1 first showed up on the Centers for Disease Control and Prevention’s COVID variant tracker in late July, right as cases began to surge. Although the summer surge of COVID hospitalizations has been on the decline for several weeks, HV.1’s presence has continued to grow quietly, yet steadily.

How contagious is the HV.1 variant?

Some experts have suggested that HV.1 might spread more easily than some of its predecessors and that it appears as though it may have the potential to bypass prior immunity — hence its increased presence across the U.S.

“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, M.D., Ph.D., director of the Center for Virology and Vaccine Research at Beth Israel Deaconess Medical Center in Boston, told NBC.

Will HV.1 cause more serious infections?

So far, experts have not signaled that this latest variant has any unique qualities with regard to its symptoms or severity. It has not yet been linked with an uptick in severe COVID infections.

Like the variants that have been dominating in recent months, HV.1 is yet another descendant of Omicron. Given its similar characteristics to XBB variants, which also stem from Omicron, experts have not expressed heightened concern for its potential to cause serious infections, at least not yet.

Will the new COVID boosters work against HV.1?

The new COVID boosters from Pfizer and Moderna were updated to target XBB variants of the virus. Since HV.1 appears to be similar to those XBB variants, experts have suggested that the new shots will likely offer some form of added protection against the latest variant, especially for those who are more vulnerable to serious infection.

However, the shots are only as effective as their uptake, which has been dismal in the weeks following their approval and subsequent rollout. According to the CDC, just 3.5% of the U.S. population has received the updated booster.

The CDC has recommended the updated shots for everyone six months and older.