Two doses of mumps vaccine needed

TORONTO, May 17 (UPI) -- Two doses of mumps vaccine may be needed -- especially for older adolescents and young adults -- to protect from the disease, researchers in Canada advise.

Researchers at the Ontario Agency for Health Protection and Promotion, the University of Toronto, the Ontario Ministry of Health and Long-term Care and the North Bay Regional Health Unit in Ontario compared the effectiveness of one and two doses of the measles, mumps and rubella vaccine during a mumps outbreak in Ontario from September 2009 to June 2010.

Dr. Shelley Deeks of the Ontario Agency for Health Protection and Promotion and co-authors say of 134 people in Ontario with confirmed mumps, 72 percent were male and 59 percent were ages 15-24. Seventy-two percent received either no vaccine or only one dose.

The study, published in the Canadian Medical Association Journal, found those born between 1980 and 1994 were more likely than expected to become infected with mumps, especially those born between 1985 and 1991.

"The clustering of cases, particularly among people born between 1985 and 1991, reflects the susceptible cohort," Deeks says in a statement. "In addition, the active social lifestyle of this age group may have facilitated the transmission of the disease."