By Robert Preidt
"Vaccination is the centerpiece of current public health strategy against mumps," said study co-author Joseph Lewnard, a postdoctoral research fellow with the Harvard School of Public Health's Center for Communicable Disease Dynamics.
"Knowing that protection wanes in the long term can help inform how we deploy vaccines to prevent or contain future outbreaks," he added in a Harvard news release.
For the study, Lewnard and his colleagues analyzed data from six studies of mumps vaccine effectiveness that were conducted in the United States and Europe. The investigators concluded that immunization against mumps lasts an average of 27 years after the last dose of vaccine.
The researchers also estimated that 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.
Further analyses indicated that weakening immunity to mumps played a major role in the recent re-emergence of mumps among young adults.
Just earlier this month, thousands of people may have been exposed to mumps during a cheerleading competition in Dallas, though no actual cases had been reported as the incubation period for infection was ending.
The latest findings suggest that, in addition to the recommended two doses of mumps vaccine in childhood, adding a third dose or booster shots at age 18 could help maintain protection against this highly contagious virus.
Few people will develop serious complications from the mumps, which causes the glands between your ears and jaw to swell.
But, the most serious potential complication of mumps is inflammation of the brain, which can lead to death or permanent disability, according to the researchers.
Also, inflammation of the membranes covering the brain and spinal cord, and loss of hearing can also occur, and in rare cases, this hearing loss can be permanent, the researchers said.
The analysis was published March 21 in the journal Science Translational Medicine.