If you've already been vaccinated for measles, do you need to get a booster now that it's spreading in the US?

About three out of 100 people who get both doses of the MMR vaccine will still get measles if they’re exposed to the virus, according to the CDC. “If someone does get measles after vaccination, the disease is typically milder than if someone who is unvaccinated acquires the infection,” Dr. Kulkarni says.