Marjorie Ingall has an excellent post on a recent measles outbreak in San Diego. A child who wasn't vaccinated because his parents didn't want him to be went to Switzerland and caught the measles. His siblings and friends subsequently became ill and only a costly intervention on the part of the city of San Diego stopped a further outbreak.
Any link between vaccinations and autism has been disproven and discredited. Vaccinations protect children from diseases that endanger their lives and those of their peers. I'm about to launch into a serious rant which isn't going to help anyone, so I'll stop. But there it is: Vaccinate.