The official definition of "vaccine" has not changed. The CDC clarified the definition due to misinformation. The pneumonia shot, rubella, measles, mumps shots, the flu shot, the hepatitis A and B shots, the mumps shots... all of these are like the covid shots in that they provide functional immunity and not sterilizing immunity.
Anti-covid-vaxers spread misinformation that the covid vaccine was not a vaccine because (like all of our vaccines except the chickenpox vaccine) the covid vaccine did not provide sterilizing immunity.
The CDC did not change the meaning of a vaccine but clarified to combat the lie.
incorrect