Many of the cases of measles were, in fact, brought home by unvaccinated people who traveled to other countries and brought back measles as a souvenir. We can thank the anti-vax fanatics for this one. Everyone should be vaccinated for measles, mumps, rubella, etc.
There are plenty of diseases coming across our border, though. What happens if, among the illegals pouring across the border, some have malaria? And then our native mosquitoes catch the malaria from them? Malaria used to be a major killer in this country before we eliminated it by killing all the infected mosquitoes. The mosquitoes that can catch malaria are still around—they just aren’t sick, these days.
The unvaccinated people primarily hurt themselves with their own stupidity. Point is, a measles vaccine greatly reduces the odds of you coming down with measles, even if you still get measles with the vaccine in you, which does happen, you tend to have a shorter, milder case. The other factor to consider about measles is that if you go through life until adulthood with zero measles exposure until adulthood, your first exposure can be really dangerous.
Even moreso, thimerosol is no longer used in MMR vaccines.