THE congenital rubella syndrome, originally described by Gregg in 19411 and amply confirmed and documented since then by extensive studies, represents by far the major problem of rubella as a disease. It is now well established that maternal rubella infection during the first trimester of pregnancy is associated with a high incidence of various congenital malformations, stillbirths, and abortions. The rubella epidemic in the United States in 1964, and its toll of many thousand cases of fetal wastage and birth defects, further stressed the urgent need for an effective means of immunization against the disease in order to protect rubella susceptible women before the next epidemic, generally expected in 1970.
Prospects for developing a rubella vaccine originated in 1962 with the report of successful rubella virus isolation in tissue cultures by two independent research groups at Walter Reed2 and at Harvard.3
Since attempts to develop an inactivated