抄録
A large number of baby with rubella syndrome was observed after rubella epidemic of 1963 in United States of America and of 1965 in Okinawa. However, rubella syndrome babies were scarcely found in Japan, although the outbreak swept over the whole country from 1965 to 1967. In this situation, it is of interest to know the immunity of pregnant women to the virus at the time when epidemic occured. Recently, rubella epidemic in Sendai area occured in 1961 and 1966 to 67. Therefore, HI antibodies of sera obtained from pregnant women in 1962, next year of epidemie, and in 1965, the year before epidemic, were retrospectively examined. As a result, HI antibody with moderate titer against rubella virus was demonstrated in all of the sera tested, although most of children showed the high titer more than 1:512 next year of epidemic. Thus it is suggested that pregnant women in Sendai might be scarcely infected with the virus at the rubella epidemics, because they had acquired the immunity before the epidemics. It may be concluded that immunity of pregnant women is the most important factor to influence the occurence of rubella syndrome.
