[Comparison of cost and benefits of each model for rubella immunization in Japan]

MMR (measles-mumps-rubella) immunization in Japan was suspended in 1993 due to the high incidence of mumps meningitis as a complication. As a result, immunization coverage for rubella still remains at the 50-60% level in Japan. One way to increase the coverage rate is to increase the frequency of immunization. We calculated the predicted positivity rate of the antibody and cost and the benefits is three models of double vaccination, i.e., vaccination twice. The first model consists of simply two identical vaccinations. The second model consists of two vaccinations with mass vaccination at school for the second immunization. The third model consists of two vaccinations with screening of the urinary antibody for rubella in the second immunization. To calculate the predicted values we used coefficients from Ibara City. The predicted positivity rates and cost increases ranged from 60% to 90% and from 7.3 billion to 12.8 billion yen from the first to third models, respectively. Screening for the urinary antibody should be much cheaper than the presumed price because more than a million subjects will be screened. Since it would cost less than half the price, the third model should be best for the positivity rate of the antibody and cost and benefits. Therefore, we think that third model is the best correction until MMR immunization can be reintroduced.