Photo by T. F. Ricketts [Public domain], via Wikimedia Commons
Measles is a viral, infectious disease. It is the most contagious of all infectious diseases. In the pre-vaccine era, measles affected nearly every individual during childhood. (ECDC). About 97% of exposed individuals who receive both vaccinations will not get measles, and neither will about 93% of those with only one vaccination (CDC 2016).