There’s a clear explanation for why those under 15 months are most affected: The typical age for a first MMR vaccine is between 12 and 15 months old, as babies are too young and weak to get inoculated. In addition to being more at risk of measles for lack of a vaccine, babies are also more vulnerable to the disease because it affects children more severely. When young children get the measles, they’re more likely to be hospitalized, die, or end up with pneumonia, hearing loss or lifelong brain damage.
