Cost-effectiveness evaluation of measles immunization strategies on a college campus

Since live rubeola vaccine became available in 1963, routine immunization of children at age 15 months has been the recommended strategy for eliminating measles in the United States. However, due to increasing measles outbreaks, especially among previously immunized populations, the Immunization Practices Advisory Committee (ACIP) recently recommended modifying the one-dose measles vaccination policy to a two-dose schedule, one at 15 months and one at age 5 or 6 years. To address the present college population, ACIP recommended vaccinating all college students who lack proof of immunity. We used the methods of decision analysis to examine the cost effectiveness of implementing such a program in a specific college population, namely, students at the University of California at Los Angeles (UCLA). We developed a model to examine three possible vaccination strategies: "wait," "screen," and "vaccinate all." Estimates of probabilities and cost were derived from several outbreaks at UCLA as well as statewide data. In the baseline case, the least expensive strategy is to wait until an outbreak occurs before implementing a vaccination program. The additional cost incurred by screening per measles case avoided is $122,871. However, using sensitivity analysis, we found that the overall cost of elective vaccination strategies is driven by the cost of the vaccine itself. If vaccine could be provided at a nominal cost to the university, a strategy of vaccinating all students without proof of immunity (by either history of two vaccinations or positive titer) would provide the high level of immunity needed to prevent outbreaks and still be most cost effective ($16,644 per measles case avoided).