[Accumulative vaccination rate of rubella and positive antibody rate in an area of Japan--future problems with rubella].

The rubella vaccination rate remarkably decreased in Japan after a revised vaccination law was passed in 1994, as a result of which individual vaccination replaced mass vaccination at each school. We investigated the rubella antibody of 887 students and the accumulative rubella vaccination rate in an area of Okayama. The vaccination rate in Ibara, where children were inoculated individually, was 22.8%. In contrast, in Yoshii, where the vaccination was done as mass at each school, the rate was 89.8%. After 2003, when the transit period of the law ends, children 12-90 months of age will be the subjects for rubella vaccine. We presume that the vaccination rate in the future will reach 40-50% through accumulative vaccination. Such a rate of vaccination cannot prevent rubella epidemics and congenital rubella syndrome. In addition, an individual's rubella vaccination is generally done once during lifetime. We doubt whether the immune response induced by a vaccine can be maintained for more than 20 years without boosting. We think that a second vaccination is necessary for at least young girls, and this should be performed as mass at each school.