"Flu shots", aka seasonal flu vaccine.
https://www.cdc.gov/flu/prevent/keyfacts.htm
It seems that your personal belief of what a vaccine is does not match the real concept of what a vaccine is and always was.
Immunity: Protection from an infectious disease. If you are immune to a disease, you can be exposed to it without becoming infected. Vaccine: A product that stimulates a person’s immune system to produce immunity to a specific disease
I'm not sure you hit an eventual consistency thing while you read the source you cited, but the definition of a vaccine in it does not match your definition.
A vaccine, according to the CDC source you quoted, is:
> Vaccine: A preparation that is used to stimulate the body’s immune response against diseases. (...)
Keep in mind that your personal definition of a vaccine does not match how most vaccines work, if any vaccine at all.