A friend of mine, many years ago, remarked that the very safest thing would be not to vaccinate one's own children while making sure that all other children were vaccinated. Given that she wasn't the absolute dictator of the world and didn't have much faith in the herd immunity in her immediate neighborhood, she went ahead and had her children vaccinated and hoped that others would do so for their children.

I assume it's not necessary to unpack that anecdote in this venue.