A recent study shows close, repeated contact with a person with mumps can overwhelm the mumps vaccine.
The study, published in The New England Journal of Medicine, comes after a face-to-face educational technique used among Orthodox Jews apparently led to an outbreak of mumps in 2009 and 2010, despite widespread vaccination, Reuters reports. In a one-year period beginning June 2009, 3,502 cases were reported in New Jersey, New York City and New York's Orange and Rockland counties. The study examined 1,648 of those cases--almost all in Orthodox Jews--and found 89% had received two doses of the vaccine and 8% received one dose.
Many of the individuals attended a religious school where they practiced an intense training technique called yeshiva. This technique involves close contact with a partner across a narrow table; partners change frequently.
"The risk of infection with mumps may be higher when the exposure dose of virus is large or intensely transmitted," the report says (as quoted by Reuters).
This prolonged, face-to-face contact apparently overcame the protection the vaccine provided. The study did find high rates of two-dose coverage reduced the severity of the disease and the transmission to people in settings of less exposure. And because the mumps didn't spread to other communities, it shows the vaccine, in most cases, is effective.
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