STUDIES involving small closed population groups have demonstrated the safety and antigenic efficacy of an attenuated rubella virus vaccine, HPV-77,1 and derivatives of it grown in duck embryo (DE) tissue culture.2 The first large scale trial in Taiwan,3 early in 1968, provided confirmation of earlier findings. The study to be described in this report represents an open field trial of HPV-77-DE 5 (Merck). It was carried out at the peak of rubella incidence in a community of approximately 60,000 people located in southwestern Connecticut.
Study Population and Methods
Letters explaining the program of study were sent to the parents of all children from 1 through 8 years of age. Vaccination was offered on a voluntary basis, excluding only those children with a known history of rubella or with a medical contraindication. Vaccination clinics were held in a local school on two successive weekends with follow-up visits eight