The dominant #SARSCoV2 variant in the US will soon be KP.3. A KP.2 vaccine induced >3-fold neutralizing titers vs KP.3 compared w/ a JN.1 vaccine (mice) 2 companies asserted they would be ready with a KP.2 vaccine But the FDA is going with a JN.1 vaccine www.fda.gov/media/179144/download pic.twitter.com/BsGLhjIbuQ

We announced today that we have submitted an application to the U.S. FDA for review of our updated COVID-19 vaccine formula, targeting the SARS-CoV-2 variant JN.1. The submission is based on guidance from the U.S. FDA, which advised that COVID-19 vaccines should be updated to a… pic.twitter.com/nk21pGmK9J

Pfizer's own data from the meeting on booster antigen selection shows a KP.2 type has 100-200% higher titers against the two strongest new lineages than a JN.1 type in a mouse model. Yet the committee still chose JN.1... hard for me to understand this decion. pic.twitter.com/83nlN9UPnj

Want to immediately drop ~25% of your neutralization titer on an updated vaccine? Don't include F456L. This Class 1 AB escape mutation was highly successful last year on XBB, and is again this year on JN.1 (evolved AGAIN), but will not be in the updated shots. Foolish decision. pic.twitter.com/V1W3Hwsg9W