Being vaccinated COULD be correlated with being less healthy just in that old people might be more likely to be vaccinated and young people more likely to "take their chances", and there are few things less healthy than being old.
My perception was that most infants all over the world now receive shots like MMR, TDaP and IPV. The herd immunity gained through this exercise automatically makes us less susceptible to certain diseases which were widespread even 50-60 years ago, and in turn, more healthy, even at old age.
> Being vaccinated is also directly correlated with being healthy.
Source?
I've shared my perspective in response to the other comment.