Lilly, I feel the same in that i'd rather more of the responsibility falls on adults to boost herd immunity, rather than babies. Our bodies have already been exposed to so many toxins in our lifetime- what's a few more! Compared with a 6 week old getting pumped full of vaccine!
I'm pretty sure rubella immunity wanes as most women I know (inc myself) have had to have boosters. Unless its because as kids we were never immunised against it, instead we all had the illness (well most of us at least had mumps and measles), so maybe because we only had the shot in high school we needed another one to make it work properly or something? Also WC obviously isn't forever. I have no idea about others.
Anyway I believe in herd immunity, but I do believe there needs to be more emphasis on adults being up to date. I dont believe most are up to date at all- especially with WC. Health professionals-yes, but general population I doubt it. It is widely known that most babies catch WC From their parents or close relatives, not from unvaxxed kids, so in the WC battle I really think this is where they need to target. Apparently the reason parents no longer get the vaccine free isn't because it's not working but because it's not 'cost effective', there are only a handful of deaths a year so it's not worth the govt subsidising it! Anyway, I dunno if maybe part of the reason these diseases are coming back now is because OUR immunity is starting to wear off? I dunno?