Eggshell-inspired biomineralization generates vaccines that do not require refrigeration.

We're not gonna bake it: In situ biomineralization creates an egg-like shell on vaccine particles to improve their thermostability. Different from the bare vaccine (squares), the biomineralized vaccine (red circles) can be stored at ambient temperature without refrigeration for up to a week and retain biological activity both in vitro (see graph), as well as in a mouse model.