Though BA.5 still accounts for most U.S. Covid-19 cases, percentages are rising for the other omicron variants circulating throughout the country, per the CDC.
"The ones that are particularly concerning are BQ.1 and another related one called BQ.1.1. Those are two that are expanding fairly rapidly in the United States," according to Roy Gulick, chief of the division of infectious disease at Weill Cornell Medicine and NewYork-Presbyterian Hospital.
Internationally, another concerning variant, XBB, which first emerged in Singapore and hasn't been detected in the U.S., is being closely watched worldwide as it spreads quickly in other countries.
The nickname refers to the letters that are used to define the variants like B, X and Q, which would rack up many points in a game of Scrabble.
Health professionals are keeping a close eye on BQ.1, BQ.1.1 and BA.4.6, says Gulick.
"What these three variants have in common, so the two BQs plus the 4.6, and a couple of others, is that they are more resistant to the monoclonal antibodies that we've been using," he says.
The "Scrabble" variants are very resistant to Bebtelovimab, a therapy that is commonly used and recommended as a treatment for Covid-19, especially in patients who cannot take antivirals like Paxlovid or remdesivir, according to Gulick.
Their evasive nature will likely make Bebtelovimab ineffective in patients with Covid-19 infections from those variants, he adds.
Simultaneously, monoclonal antibodies, like Evusheld, that are used as prevention for people who can't take or don't respond well to vaccines, including highly immunocompromised people, are losing "all efficacy against these more recent variants," says Gulick.
"Both of these pose threats either to people who are being treated with Covid today or where we're trying to prevent Covid today," he notes.
Thankfully, antivirals, including Paxlovid and remdesivir, still provide full protection against these variants at this time, says Gulick. "They're powerful tools that people who are at risk really should make use of," he says.
A few preventative measures to consider are getting a bivalent booster, which may offer some level of protection against the newer variants, and wearing masks in public places, he says.
"We are concerned that these new variants, because they will render some of the monoclonal [antibodies] not effective for prevention or treatment, that this could lead to increased cases," he says.
"Unfortunately, as people keep saying, the virus is not over us. The virus is not done."