Here .. read this and remember it can also happen in dogs. People become so overly afraid of vaccines that they lose common sense somewhere along the line and don't protect their children:
O.C. measles outbreak spurs officials to call for immunizations - latimes.com
For those of you who think it is safe to not vaccinate your pups, I strongly suggest you buy him/her a bubble to live in. Definitely don't take him/her to dog parks!!