Third Dose of MMR Vaccine May Help to Control Mumps Outbreak

In a recent study, researchers tested a third dose of the measles-mumps-rubella (MMR) vaccine on students in an affected community in an effort to control the outbreak. In the study, 2,178 sixth- to 12th-grade students in three schools with proof of having received two previous doses of MMR vaccine were offered a third dose of the vaccine and monitored to assess mumps attack rates. The overall attack rate for all students declined from 3.93 percent in the prevaccination period to 0.13 percent after vaccination. Overall in the affected area, the attack rate declined by 75.6 percent after the intervention. And, while a decline occurred in all age groups, it was significantly greater (96 percent) among 11- to 17-year-olds, the age group targeted for vaccination, than among all other age groups. The researchers concluded that a third dose of the MMR vaccine may help control mumps outbreaks among populations with pre-existing high two-dose vaccine coverage. The study was published in the November 5 edition of Pediatrics.