> until 10 or 20 years ago
You're off by a decade and possibly two. I'm older than 20, I was vaccinated for Chickenpox. The vaccine has been commercially available for 35 years.
So I'd reiterate the question.
You're off by a decade and possibly two. I'm older than 20, I was vaccinated for Chickenpox. The vaccine has been commercially available for 35 years.
So I'd reiterate the question.
There may have been a vaccine 35 years ago (I'll take your word for it), but it was not the standard of care even ~25 years ago.
(And to be clear, I'm not advocating for exposing people to COVID, at all. You asked a very broad question upthread with an easy counter-example — chickenpox — and I provided the counterexample.)