The new KP.3 variant has climbed to 1 in 4 new COVID-19 cases nationwide, the Centers for Disease Control and Prevention estimated Friday, making it now the dominant strain of the virus nationwide. KP.
3's ascent comes as the CDC has tracked key metrics of spread from the virus now starting to trend up. Previous years have seen surges of the virus peak around August. Data from CDC's wastewater surveillance has tracked levels of the virus starting to accelerate in the West.
Emergency room visits for COVID-19 have inched up in recent weeks for all ages. COVID-19 infections are likely growing in 30 states and territories, the CDC now estimates . KP.
3 is now estimated to be outpacing the KP.2 variant, a so-called "FLiRT" strain that this week inched up to 22.5% of cases.
KP.2 had risen to dominance in previous weeks, but its growth has now slowed. Both KP.
3 and KP.2 are "very, very similar" to the JN.1 variant that had dominated this past winter's wave of infections.
"When you look at KP.2 and KP.3, they're nearly identical to each other with really one difference between the two of them," Natalie Thornburg, the chief lab official at the CDC's Coronavirus and Other Respiratory Viruses Division, said Wednesday.
Thornburg was speaking at a Food and Drug Administration meeting debating what strains should be targeted by this fall's vaccines. This difference is smaller than previous jumps in the virus, like when JN.1's parent – the highly mutated BA.
2.86 variant – first emerged la.