In Japan, mass vaccination for diphtheria, pertussis, and/or tetanus has been mandated by the Vaccination Law since 1948. In order to evaluate the efficacy of this vaccination policy, we conducted seroepidemiological studies on pertussis, diphtheria, and tetanus among individuals aged 0 - 80 years. The pertussis toxin seropositive rates of the vaccine-eligible groups and vaccine-ineligible grou...
