[Comment] Vaccine hesitancy: an evolving challenge

00:00 - 12 Jan 2026

In 2015, WHO defined vaccine hesitancy as a “delay in acceptance or refusal of vaccines despite availability of vaccination services”.1 More recently, it has been argued that the concept should be redefined as a “psychological state of indecisiveness that people may experience when making a decision regarding vaccination”,2 thereby distinguishing hesitancy from the final vaccination decision. Indeed, although hesitancy remains an internal state of indecision preceding the behavioural outcome related to vaccination, it is the actual choice a person makes about vaccination (ie, acceptance or refusal) that represents the behaviour itself.