A survey of rubella antibodies in health personnel and a report of vaccine trial.

Five hundred and seventy female health science personnel between the ages of 18 and 25 years were examined for antibodies to the rubella virus by the hemagglutination inhibition technique. Approximately 90% of the subjects had a titre of 1:20 or higher. The geometric mean titre of the positive sera was 1:251. Sixty-four of the 77 persons with an antibody of 1:20 or less volunteered to take the vaccine and were examined six weeks later for the development of antibodies. The conversion rate for the 51 persons who were negative at the dilution of 1:20 at the outset was 94%; the rate of antibody increment for the 13 persons who were positive at 1:20 at the outset was 77%. Among the 51 persons who developed antibodies, the geometric mean titre was 1:57 and among the other 13 it was 1:49. Although the trial was conducted in adult females, the number of side effects from the vaccine was remarkably scanty and insignificant. This trial would seem to emphasize the importance of avoiding the use of rubella vaccine in women of child-bearing age without first excluding pregnancy with meticulous care and using active and controllable contraceptive methods for the two months following vaccination.