Third dose of MMR vaccine can help control mumps outbreaks

(HealthDay)—A third dose of measles-mumps-rubella (MMR) vaccine is recommended in cases of mumps outbreak in which transmission is sustained despite high two-dose MMR coverage, according to research published in the July 29 issue of the U.S. Centers for Disease Control and Prevention's Morbidity and Mortality Weekly Report.

Justin P. Albertson, from the University of Illinois at Urbana-Champaign, and colleagues conducted an investigation into a confirmed mumps outbreak in 2015. They identified 317 cases of mumps during April 2015 to May 2016.

The researchers recommended a third MMR vaccine because of sustained transmission in a population with high two-dose coverage with MMR. The Advisory Committee on Immunization Practices did not formally recommend for or against use of a third dose. However, the CDC provided guidelines for use of a third dose as a control measure during outbreaks in a setting in which transmission is sustained despite high two-dose MMR coverage. The final case in this outbreak occurred in May 2016.

"Although evidence of its effectiveness is needed, a third dose of MMR vaccine may be considered as a control measure during mumps outbreaks occurring in settings in which persons are in close contact with one another, when transmission is sustained despite high two-dose MMR coverage, and when traditional control measures fail to slow transmission," the authors write.