Cost-effectiveness analyses of monovalent mumps vaccination programs for Japanese children.

BACKGROUND

The most common preventative measure against mumps is vaccination with mumps vaccine. Over 122 countries have implemented mumps vaccine routine immunization programs, mostly via Measles-Mumps-Rubella (MMR) vaccine. In Japan, the unexpectedly high incidence of aseptic meningitis caused by mumps vaccine led to the discontinuation of the MMR national vaccination program in 1993, inadvertently resulting in the re-emergence of mumps. Plans of introducing monovalent mumps vaccine into routine vaccination schedule have become one of the emerging topics in health policy that has warranted the need in evaluating its value for money.

METHODS

We conducted cost-effectiveness analyses with Markov model and calculated incremental cost-effectiveness ratios (ICERs) of two different vaccination programs (a single-dose program at one-year-old, a two-dose program with second dose uptakes at five) compared to status quo from both payers' and societal perspectives. Transition probabilities and utility weights in estimating quality-adjusted life-year (QALY), and disease treatment costs were either estimated or obtained from literature. Costs per vaccination were assumed at ¥6140 (US$58;1US$ = ¥106).

RESULTS

Both programs reduce disease treatment costs compared to status quo, while the reduction cannot offset vaccination cost. ICER of either program is found to be under ¥5,000,000 (US$47,170)/QALY willingness-to-pay (WTP) threshold from either perspective. Results of probabilistic sensitivity analyses expressed by net monetary benefit indicated that at the WTP threshold, the acceptability is at 92.6% for two-dose vaccination program, 0% for single-dose vaccination program, and 7.4% for current no vaccination program. Two-dose program was optimal among the alternatives. One-way sensitivity analyses revealed that proportion of mumps-related hearing loss among mumps cases and vaccine effectiveness (VE) were key variables in changing the ICERs.

CONCLUSION

Routine vaccination program of single- and two-dose programs were cost-effective from both payers' and societal perspectives. Between the two, the two-dose vaccination program was observed to be more favorable.