Serological response to rubella revaccination in adolescent females

The study's purpose was to utilize ELISA in determining rubella susceptibility in teenagers who are seronegative by HI. Ten previously vaccinated, seronegative adolescent females were revaccinated with RA 27/3 and their IgG and IgM responses measured by ELISA. Before revaccination, all 10 were seronegative for rubella by HI (less than 1:10). However, by ELISA, six showed an IgG and no IgM levels. After reimmunization, three showed a significant IgM response by day 6, indicating primary rubella exposure. The remaining seven females failed to demonstrate an IgM response; however, the failure was consistent with a history of prior rubella vaccination. Peak IgG responses were noted by day 12 in nine of the females. The remaining teenager failed to show an IgG response and was considered a vaccine failure. This study confirms the superiority of ELISA as compared to HI titers in determining rubella susceptibility.