The new KP. 3 variant has risen to 1 of the 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 comes as the CDC has been tracking key signs of the virus’s spread that are now beginning to appear. In previous years, outbreaks of the virus peaked around August.
CDC wastewater surveillance data has tracked virus levels beginning to rise in the West. Emergency room visits for COVID-19 have increased in recent weeks for all ages. COVID-19 infections are most likely in 30 states and territories, according to the CDC now. Dear.
KP. 3 is now estimated to surpass the KP. 2 variant, a strain known as “FLiRT” that has reached 22. 5% of cases this week. KP. 2 had been dominant in recent weeks, but its expansion has now slowed.
The KP. 3 and KP. 2 variants are “very, very similar” to the JN. 1 variant that dominated last winter’s wave of infections.
“When you look at KP. 2 and KP. 3, they’re almost equal to each other, with a difference between the two,” Natalie Thornburg, lead laboratory director for the CDC’s Division of Coronavirus and Other Respiratory Viruses, said Wednesday.
Thornburg spoke at a Food and Drug Administration meeting to discuss which strains this fall’s vaccines will target.
This difference is smaller than in the past in the virus, such as when JN. 1’s parent, the highly mutated BA. 2. 86 variant, first emerged last year.
However, KP. 2 and KP. 3 are not identical either. Early insights suggest that KP. 3 mutations may be more effective at evading immunity.
“The JN. 1 and KP. 2 viruses are very overlapping. And KP. 3 is very close, although certainly not above,” Thornburg said.
The KP. 3 buildup comes as the FDA announced Friday that it had to order shots this fall to keep up with the JN. 1 variant that was dominant earlier this year, thus rejecting a new formula intended for KP. 2 variant.
“Yes, we say we shouldn’t go after strains, but we pay an incredibly high price for mRNA vaccines so we can have the most up-to-date vaccines,” the FDA’s Peter Marks said at the meeting.
Moderna had submitted data from animal studies suggesting that its shot targeting KP. 2 offered coverage against newer variants, compared to a shot designed for JN. 1. Pfizer’s vaccine against KP. 2 elicited higher antibody responses against JN. 1 variants, adding KP. 3.
“If this evolves again in the fall, won’t we be a little bit closer?” said Marks.
But the FDA eventually approved the KP. 2 shots, after the company’s advisers worried about their effectiveness in boosting immunity against future strains compared to JN. 1.