SUMMARYThis report summarizes closed, family, and open studies conducted sequentially over a 10 month period with the Cendehill rubella virus vaccine in more than 16,000 children and adolescents. This strain of rubella was attenuated by serial propagation on primary rabbit kidney cell cultures. Inoculation of the Cendehill vaccine produced seroconversion in 97 % of the 3589 susceptible (seronegative) vaccinated persons. There was no spread of the virus to susceptible controls living in close contact with those vaccinated. The vaccine was well tolerated. No arthritis or arthralgia occurred in 860 female subjects 13-18 years of age who were included in the study. The Cendehill vaccine would appear to meet the requirements of an acceptable vaccine.