Study Questions Durability of MMR Vaccine

The effectiveness of the mumps vaccine wanes at an average of 27 years after the last dose, potentially explaining the resurgence of cases over the past 11 years, researchers said here.

According to an analysis of epidemiological studies, the introduction of the measles-mumps-rubella (MMR) vaccine in the 1960s lowered case rates by more than 99%, according to the CDC, and annual cases in recent years have typically numbered in the hundreds, reported Joseph Lewnard, PhD, and Yonathan H. Grad, MD, PhD, both of the Harvard TH Chan School of Public Health in Boston.

But mumps cases spiked in 2006 and again in 2016 and 2017, they said in a presentation at the annual IDWeek meeting, sponsored jointly by the Infectious Diseases Society of America (IDSA), the Pediatric Infectious Diseases Society (PIDS), the Society for Healthcare Epidemiology of America (SHEA), and the HIV Medicine Association (HIVMA).

The findings point to the need for booster doses in adults, according to Lewnard. "If you want to put mumps on the track to elimination, it's not an unreasonable expectation," he stated.

"We've largely eliminated it, but the [MMR] vaccine is not a perfect dose," said Paul Offit, MD, of the Children's Hospital of Philadelphia, to MedPage Today.

The CDC received reports of more than 6,300 cases in 2016 compared with just 229 in 2012.