Well, the definition of vaccine changed late last year after it was found that the Covid vaccinations did not prevent infections. Definition before late-2020:

Well, the definition of vaccine changed late last year after it was found that the Covid vaccinations did not prevent infections. Definition before late-2020: "a product that stimulates a person's immune system to produce immunity to a specific disease, thereby protecting against that disease", To "a preparation used to stimulate the body's immune response against a specific disease". Now, we are realising that the Covid vaccines are helpless against the new variants, so I guess the definition will be changed even further. Compared to something like the Smallpox vaccine (lifelong/multi-decade immunity), the Covid vaccine is mostly useless.