An experimental live, attenuated rubella vaccine, RA 27/3, was compared with HPV-77, DE-5 rubella vaccine (Meruvax) in children in an open school setting. Seroconversion of RA 27/3 vaccines administered by either intranasal or subcutaneous route and HPV-77, DE-5 given subcutaneously was 95% or greater as measured by hemagglutination-inhibition antibody (HI). However, RA 27/3 vaccine produced significantly greater seroconversion rates and titer levels by complement-fixation antibody (CF) testing, when compared with HPV-77, DE-5 vaccine. No serious reactions were noted, and there were no joint reactions in any study group during the 28-day postimmunization follow-up period or upon recontacting vaccine recipients one year later. Intranasal immunization was well tolerated.