Mumps Postexposure Prophylaxis with a Third Dose of Measles-Mumps-Rubella Vaccine, Orange County, New York, USA

Amy Parker Fiebelkorn

, Jacqueline Lawler, Aaron T. Curns, Christina Brandeburg, and Gregory S. Wallace

Author affiliations: Centers for Disease Control and Prevention, Atlanta, GA, USA (A. Parker Fiebelkorn, A.T. Curns, G.S. Wallace); Orange County Health Department, Goshen, New York, USA (J. Lawler, C. Brandeburg)

Abstract

Although the measles-mumps-rubella (MMR) vaccine is not recommended for mumps postexposure prophylaxis (PEP), data on its effectiveness are limited. During the 2009–2010 mumps outbreak in the northeastern United States, we assessed effectiveness of PEP with a third dose of MMR vaccine among contacts in Orthodox Jewish households who were given a third dose within 5 days of mumps onset in the household’s index patient. We compared mumps attack rates between persons who received a third MMR dose during the first incubation period after onset in the index patient and 2-dose vaccinated persons who had not. Twenty-eight (11.7%) of 239 eligible household members received a third MMR dose as PEP. Mumps attack rates were 0% among third-dose recipients versus 5.2% among 2-dose recipients without PEP (p = 0.57). Although a third MMR dose administered as PEP did not have a significant effect, it may offer some benefits in specific outbreak contexts.

Mumps is an acute, viral illness that classically is manifested as parotitis and can cause severe complications, including encephalitis (1), deafness (2,3), and orchitis (4). In 1977, the Advisory Committee on Immunization Practices (ACIP) recommended 1 mumps vaccine dose for routine childhood vaccination, and in 1989, the committee recommended that 2 doses of measles-mumps-rubella (MMR) vaccine be given to school-aged children and select high-risk groups for improved measles control (5). ACIP does not recommend administering MMR vaccine during mumps outbreaks as postexposure prophylaxis (i.e., vaccine administered during a brief window after exposure to prevent mumps infection) (5). Antibody response to the mumps component of MMR vaccine is generally believed to develop too late to provide effective prophylaxis after a person has been exposed to suspected mumps (6,7), but data are insufficient for to assessing a possible prophylactic effect.
During 2009–2010, a large mumps outbreak affected 3,502 persons in the Orthodox Jewish community in the northeastern United States. Students, from elementary school through college, had 2,370 (67.7%) cases; of these case-patients, 85% had received the recommended 2 doses of MMR vaccine (8). Yeshivas (i.e., private, traditional Jewish schools with extended school days) and households characterized by large families, typical in the Orthodox Jewish community, were the primary settings for mumps transmission (8). The objective of this study was to assess secondary mumps attack rates among Orthodox Jewish household contacts in Orange County, New York, who received PEP with a third dose of MMR vaccine within 5 days of mumps introduction into a household by a family member, and compare them with household contacts of persons who had received 2 previous MMR doses and did not receive PEP.