Effects of a Public Subsidization Program for Mumps Vaccine on Reducing the Disease Burden in Nagoya City, Japan.

Nagoya City initiated a public subsidization program for mumps vaccination using either Torii- or Hoshino-strains in August 2010. To demonstrate the effects of the program, we used publicly available information from Nagoya City to investigate the changes in immunization rate and numbers of patients who developed post-immunization adverse reactions, including post-vaccinal aseptic meningitis, in the 7 years since its initiation. We also investigated the numbers of mumps patients reported during this period by sentinel sites in a national database. The immunization rate in 1-year-old children increased from 24.3% before the program to 91.0% after 7 years. The mean numbers of reported mumps patients per sentinel site in 1-year-old to preschool children, as the age groups targeted by the program, were 12.9 in the 7 years before the program and 4.93 in the 7 years after initiation of the program, showing a significant decrease of 1/2.6 (p = 0.01). The number of vaccinations during the 6.5-year period was 140,316, with only one case of aseptic meningitis reported (0.7 cases/100,000 vaccinations). No other serious adverse reactions were observed. The present findings demonstrate that the public subsidization program in Nagoya City is an effective and safe measure against mumps in children.