No definition is fine, just how we use the term, similar to calling photocopies "Xeroxes" or facial tissue "Kleenex". Yes, no vaccine itself works directly against a virus, they depend on stimulating the immune system to do that, and I've never said that any vaccine directly stops a virus so what's your point?
FYI:
Moderna COVID-19 Vaccine, is the officially FDA approved product name, for this, a vaccine that elicits in immune response against the COVID-19 spike protein.
Also I think you screenshot is NOT something you looked up on the OED website, but something you found on one of your "Fake News" websites. I'd love to see the link because that parenthetical statement seems to be an insert.
Here's what I get from OED, and it doesn't have that statement:
https://www.oxfordreference.com/view/10.1093/oi/authority.20110803115026742
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