In this Thursday, Jan. 29, 2015 photo, pediatrician Charles Goodman holds a dose of the measles-mumps-rubella, or MMR, vaccine at his practice in Northridge, Calif. The vaccine is 99 percent effective at preventing measles, which spreads easily through the air and in enclosed spaces. Symptoms include fever, runny nose, cough and a rash all over the body. (AP Photo/Damian Dovarganes)