This. Is. FASCINATING: βThe vaccine, which contains dead versions of the bacterium Paenibacillus larvae, comes in the form of food. The vaccine is incorporated into royal jelly, a sugar feed given to queen bees. Once they ingest it, the vaccine is then deposited in their ovaries, giving developing larvae immunity as they hatch.β https://www.nytimes.com/2023/01/07/science/honeybee-vaccine.html?smid=nytcore-ios-share&referringSource=articleShare