They don’t know, they merely “believe”?

U.S. health officials believe Pfizer and Moderna’s updated boosters will provide stronger protection against infection and disease this winter than the first generation of vaccines because they target omicron BA.5, which is causing most infections right now.

….

Novavax has not presented real-world efficacy data on how its shots perform against BA.5, one of the most immune evasive variants of Covid yet. Pfizer and Moderna also do not have real-world data on how their new boosters perform against BA.5.

Source: FDA authorizes Novavax’s Covid shots as mix-and-match booster to Pfizer or Moderna

Having some persuasive data might do a better job than an appeal to authorities (who have been wrong about much but) who believe it’s a good idea.

Coldstreams Skeptic