I would like to be educated in a certain topic I don’t know to much about. Just saw a post about a 4…

I would like to be educated in a certain topic I don’t know to much about. Just saw a post about a 4 month old dying from meningitis who likely caught it from an unvaccinated boy from daycare. My question is was the unvaccinated boy not showing symptoms of meningitis?! Like does it not effect the older kids? Is just a minor cold to them or something?