The MMR vaccine is split into 2 doses - the first is given to children when they're about 1 year old. The second is given when they are 4-6 years old.

Sometimes the conversation on vaccines misses these facts. Herd immunity is what protects the babies the most. That's probably why we're seeing so many children deaths so far.

In all, there have been nine reported measles deaths this year in the US, eight of which have been confirmed by state officials. The deaths include the baby’s death in Wisconsin, the child’s death in New York, and seven deaths (six confirmed) in Pennsylvania, including two babies, a healthy teen, and several adults with underlying health conditions.