To me, the urgency with the vaccine is more about trying to reduce the number of people who can host the vaccine and allow it to mutate into another variant. It certainly helps protect people from the virus, and while college-aged kids are pretty low risk, unvaccinated kids are a decent sized population group that could allow this variant to mutate into another variant that's more resistant to a vaccine or a variant that is more effective towards younger kids, particularly those who aren't currently eligible for vaccines at all.