A new FLiRT variant called KP.2 is causing concern in the United States as more than a third of COVID-19 cases are now estimated to be linked to this strain. The Centers for Disease Control and Prevention (CDC) predicts that the KP.2 variant, along with another FLiRT mutation strain called KP.1.1, make up 35.3% of infections this week, a significant increase from 7.1% just a month ago.
Despite being the most predominant variant, KP.2 is not causing an increase in infections as transmission of the virus is low. The emergence of these FLiRT variants has led the Food and Drug Administration (FDA) to delay a crucial step in selecting the strain to target with the upcoming fall’s COVID-19 vaccines.
FLiRT variants are named for their two distinctive mutations F456L and R346T and are descendants of the JN.1 variant that swept over the winter. The CDC has stated that there are no signs that the KP.2 variant would cause more severe illness than other strains. However, a draft study from Japan found that the KP.2 variant appears to evade antibodies better than the JN.1 variant, possibly explaining its rise in cases.
While the CDC has not altered its vaccine recommendations in response to the FLiRT variants, the FDA is postponing a meeting to select a vaccine target for the fall. Pharmaceutical companies such as Pfizer, Moderna, and Novavax are all working on vaccines and updates targeted at the FLiRT variants, with Novavax reporting promising cross-reactivity for KP.2. As the situation continues to evolve, health officials are closely monitoring the spread of these new variants to determine the best course of action.
“Infuriatingly humble tv expert. Friendly student. Travel fanatic. Bacon fan. Unable to type with boxing gloves on.”