Most of the college students who got the mumps in a big outbreak in 2006 had received the recommended two vaccine shots, according to a study that raises questions about whether a new vaccine or another booster shot is needed.
The outbreak was the biggest in the United States since shortly before states began requiring a second shot for youngsters in 1990.
Nearly 6,600 people became sick with the mumps, mostly in eight Midwestern states, and the hardest-hit group was college students ages 18 to 24. Of those in that group who knew whether they had been vaccinated, 84 percent had had two mumps shots, according to the study by the Centers for Disease Control and Prevention and state health departments.
That “two-dose vaccine failure” startled public health experts, who hadn’t expected immunity to wane so soon — if at all.
The mumps virus involved was a relatively new strain in the U.S., not the one targeted by the vaccine, although there’s evidence the shots work well against the new strain.
The researchers, reporting in today’s New England Journal of Medicine, note the virus likely came from travelers or students from the United Kingdom, where mumps shots are voluntary.
Mumps is spread by respiratory secretions and saliva among people in close contact.
It might not be cost effective to give everyone a third shot, but it should be considered for college students, said Dr. Stephen Marcella, an epidemiologist at University of Medicine and Dentistry of New Jersey’s School of Public Health.
