In this study a venous blood specimen was drawn and, at the same time, rubella vaccine was given to 1906 schoolgirls mostly in the pre-pubertal age. To assess the pre-vaccination immune status and the effect of the vaccine, a second blood sample was taken 6 weeks later and tested for rubella HAI antibody simultaneously with the first one. RA 27/3 rubella vaccine administered by intranasal route to 81 girls produced a 100% seroconversion rate and the same vaccine strain, given by subcutaneous route to 460 girls, produced a 94.73% seroconversion rate. Among the 1, 365 schoolgirls who received subcutaneous Cendehill vaccine, the seroconversion rate was 86.68%. Side effects were mild and transient and occurred, as headache, most frequently among the girls who received RA 27/3 vaccine by intranasal route.