(Reuters) - A face-to-face educational method used among Orthodox Jews apparently led to a U.S. outbreak of mumps in 2009 and 2010 even though most of those infected had been properly vaccinated, according to a U.S. study. The outbreak, detailed in the New England Journal of Medicine, indicates how close, repeated contact with an infected person can overwhelm the mumps vaccine, the researchers said. "The risk of infection with mumps may be higher when the exposure dose of virus is large or intensely transmitted," wrote lead author Albert Barskey, of the U.S. ...
