CDC offers guidance on third MMR dose after campus mumps outbreak
The CDC recently offered guidance on a third dose of the measles-mumps-rubella vaccine to adolescents and young adults following a recent mumps outbreak at the University of Illinois, according to an MMWR report.
“No formal recommendation for or against the use of a third MMR dose has been issued by the Advisory Committee on Immunization Practices (ACIP),” Justin P. Albertson, MS, from the Illinois Department of Public Health, and colleagues wrote. “However, CDC has provided guidelines for use of a third dose as a control measure during mumps outbreaks in settings in which persons are in close contact with one another, where transmission is sustained despite high 2-dose MMR coverage, and when traditional control measures fail to slow transmission.”
The Illinois Department of Public Health (IDPH) confirmed an outbreak of mumps at the University of Illinois at Urbana-Champaign (C-UPHD) May 1, 2015. Between April 2015 and May 2016, researchers identified 317 cases on campus. The university, IDPH and the university’s McKinley Health Center recommended a third MMR vaccination due to the seasonal trends and characteristics of the population at risk.
About 50,000 students and staff members were targeted for third-dose vaccination on C-UPHD campus. A total of 8,200 doses of MMR were administered at multiple vaccination sites at the university between August 6 and 7, 2015, to determine if a third dose of MMR would prevent further exposure of mumps to healthy staff and students. In addition, the C-UPHD center administered 3,300 doses in the fall and spring semesters.
Epidemiological analysis showed that all 317 cases of mumps were associated with the university. Cases in students totaled 278 (88%), three (1%) in staff members and 36 (11%) in people not associated with the university but who had contact with students or grounds. Among the diagnosed at the time of parotitis onset, 50 patients had received three doses of MMR vaccine, 232 patients had received two doses, 12 patients had received one dose, seven patients were unvaccinated and 16 patients were unaware if they had been vaccinated. Ninety percent of the 50 patients with a third dose received it during the outbreak, and 10% had received it previously independent of this outbreak, according to the researchers.
“Currently there is no formal recommendation for a third dose of MMR vaccine during mumps outbreaks; the decision to implement this intervention needs to be carefully considered,” the researchers wrote. “In light of the recent increased incidence of mumps, CDC is gathering additional data to assess use of a third dose of vaccine to inform decision-making during outbreak responses and potential changes in the recommendations.” – by Kate Sherrer
Disclosure: The researchers report no relevant financial disclosures.