AN ATTENUATED RUBELLA VIRUS STRAIN ADAPTED TO PRIMARY RABBIT KIDNEY

Plotkin, S. A. (Wistar Institute, 39th and Spruce Sts., Philadelphia, Pa. 19104), J. Farquhar, M. Katz, A. Prinzie and T. H. Ingalls. An attenuated rubella virus strain adapted to primary rabbit kidney. Amer. J. Epid., 1968, 88: 97–102.—A rubella virus strain (Cendehill) has been passaged in primary rabbit kidney tissue culture with the goal of attenuation. Attenuation is defined as lack of clinical reaction or contagiousness after inoculation in man. Tests in children at the 51st and 61st passage levels were conducted and compared to an earlier study of the 21st passage virus. All passage levels produced nasopharyngeal virus excretion and antibody response in inoculated children; however, both were lowest after inoculation of the 61st passage. Uninoculated children showed neither virus excretion nor antibody response after contact with vacdnees given 51st passage virus. Antibody persisted at least 11 months after vaccination. Thus the 51st passage Cendehill strain appeared to be an adequate candidate strain for a live-virus rubella vaccine.