Minnesota Mumps Outbreak Largest Since 2006
This mumps outbreak at UMN parallels other mumps outbreaks on college campuses across the country in recent months, including Harvard University and Penn State University, where all of the infected students had received at least one dose of the MMR vaccine and most had received two.2 3
According to the Centers for Disease Control and Prevention (CDC), the MMR vaccine confers full protection in 78 percent of patients who receive one dose and 88 percent of patients who receive two doses.4 Studies examining the effectiveness of the mumps component of the MMR vaccine reflect that the official CDC assessment of MMR protection may be overly optimistic.5 6
|Studies examining the effectiveness of the mumps component of the MMR vaccine reflect that the official CDC assessment of MMR protection may be overly optimistic.|
A Canadian study in 2011 found that MMR effectiveness ranged from 49-82 percent after one dose and 66-88 percent after two doses, with accumulating evidence of waning immunity over time.7 In particular, the authors noted that field analyses of MMR protection in these ranges contradicted published clinical trial data reflecting 95 percent effectiveness after one dose.
The study’s finding is consistent with evidence disclosed in 2010 by whistleblowers Stephen Krahling and Joan Wlochowski, virologists employed by vaccine manufacturer Merck & Co. to test the efficacy of the mumps component of the MMR vaccine. Krahling and Wlochowski went on to file a lawsuit charging that Merck coerced them to employ fraudulent tactics, fabricate data and ultimately inflate the stated efficacy of the vaccine.8 9 10
Mumps is a highly contagious and usually mild illness, although serious complications can occur and are more likely when the disease is contracted during adulthood. The CDC currently recommends MMR doses for all children at 12-15 months and again at 4-6 years of age.11 The timing of waning immunity after these doses combined with the close living quarters and high risk of contagion in dormitory settings may contribute to the frequency of mumps outbreaks on college campuses and the increasing incidence of complications more rare among childhood cases.12
Mumps transmission can be contained by quarantining infected people, covering the nose and mouth when coughing or sneezing, not sharing drinks or utensils, and frequently washing hands and disinfecting surfaces.13