Five hundred thirty-five women living in Utah were evaluated serologically before and after a rubella immunization campaign in April 1970. Sixty-one percent of these women were pregnant. Of 33 susceptible women with household contact to vaccine recipients, one developed serologically documented rubella; however, the antibody response suggested that this illness was caused by wild rubella virus. None of 52 seronegative women without household contact to vaccinees became seropositive. One of 450 previously immune women had a fourfold rise in rubella antibody. These findings support the concept that infection of a susceptible adult with vaccine virus secondary to spread from a vaccinee is an unlikely event.
Klock LE, Spruance SL, Bailey A, McQuarrie HG, Herbertson RM, Sharp HC, Smith CB. A Clinical and Serological Study of Women Exposed to Rubella Vaccinees. Am J Dis Child. 1972;123(5):465–468. doi:10.1001/archpedi.1972.02110110093007