Hep is a herd vaccine, it was started as a preventative being given to ghetto kids who might not see health care in their entire lives.
of course it has morphed into a got to have for all kids, for one cannot be biased.
Same for Chickenpox. Originally given for daycare kids, now considered a got to.
I had chicken pox, all the kids in the house did at the same time. Later my youngest half-sibling got chickenpox again - as an adult - and it went to his brain and he nearly died. He was supposedly immune. Meh - this happens.
My youngest was vaccinated for chickenpox and yet had a horrible case (he apparently looked worse than he felt) when he was 10. Had to be home for a dozen days. School started to bitch at me to send him back, but I couldn’t until his recovery reached a certain point. He also had scarlatina when he was a baby.
When I was vaccinated for small pox I ended up with “pox” up and down that arm.
Kinda makes one wonder.