Comment by apparent
6 hours ago
The bigger issue is that someone who is 40 has likely already been exposed. I know women who had to ask to get it in their late 20's, and only succeeded after convincing the doctor they had been celibate up to that point. Apparently such a thing is relatively rare.
In either case this neither means that they are now immune against that specific strain, nor that they can't or won't get infected by another. Therefore that reasoning is flawed.