Husband hasn't gotten vaccinations since 6

Well....today I found out that my husband hasn't gotten any vaccinations since he was 6 (no earthly clue how that happend, I'm shocked). I'm so confused because I've always thought that in order to go to school you had to be up to date on your vaccinations. He's going to college and they said that we can sign a waiver saying that he doesn't want to take them - but I think he should take them. What do y'all think?