The other 2 arteries that bring blood to the brain, called the vertebral arteries, supply the brainstem. Plaque in the vertebral arteries is much less likely to break off and cause a stroke, but narrowing in the vertebral arteries can cause problems if the brainstem does not get enough blood flow.
A child should receive the first shot when he is between 12-15 months, and the second when he's between 4-6 years of age. If you're not sure if you have had the diseases or the vaccines (prior to 1971 it was given in three separate shots), you can get the MMR vaccine as an adult.
Measles, mumps, and rubella (MMR) vaccine can protect children (and adults) from all three of these diseases. Thanks to successful vaccination programs these diseases are much less common in the U.S. than they used to be. But if we stopped vaccinating they would return. Who should get MMR vaccine and when? Children should get 2 doses of MMR vaccine: First Dose: 12-15 months of age. Second Dose: 4-6 years of age (may be given earlier, if at least 28 days after the 1st dose)