Study Finds Mumps Vaccine Protection Wanes Over Time

A recent meta-analysis of six studies of mumps vaccine effectiveness conducted in the U.S. found protection against mumps lasts an average of 27 years after the last dose of the vaccine. In addition, researchers estimated 25 percent of Americans who were vaccinated against mumps as children may lose protection within about eight years, 50 percent within 19 years and 75 percent within 38 years. They also found weakening immunity to mumps played a major role in the recent reemergence of mumps among young adults. The findings suggest that in addition to the recommended two doses of mumps vaccine in childhood, adding a third dose or booster shot at age 18 could help maintain protection.