> Name another example Sure, another example is the flu vaccine as you mention. The primary aim of the flu vaccine in the U.S. medical system is to protect hig

> Name another example Sure, another example is the flu vaccine as you mention. The primary aim of the flu vaccine in the U.S. medical system is to protect high-risk people from life-threatening symptoms, even during infections from different strains. Another example is the shingles vaccine. The primary aim is to prevent severe symptoms (such as neural damage and long term pain) during a reactivation of an existing chronic infection. > It’s insane we’re changing the definition of words The semantic meaning of the word vaccine hasn't changed. All that's changed is the U.S. CDC official definition text, to clarify that the primary aim of vaccines is to activate the body's immune system, rather than solely to prevent a new specific infection. If you're curious about the language exactness, beyond the U.S. CDC, the U.S. FDA is also involved. For example, the U.S. FDA during COVID stated that a vaccine would need to be at least 50% effective for diminishing the severity of COVID-19 symptoms to obtain regulatory and marketing approval. In other words, the primary aim was to help people reduce damage; the primary aim was not to full-stop prevent infection.