Intranasal administration of RA 27/3 rubella virus vaccine. A clinical trial in young adults

Of the vaccines and inoculation routes studied for the prevention of rubella, only the RA27/3 vaccine, administered intranasally, has the ability to stimulate a humoral antibody pattern very similar to that evoked by wild rubella infection. Because information about intranasal (IN) vaccination has only been obtained using the RA 27/3 vaccine manufactured in Europe, we conducted a trial of IN vaccination among young adults using Meruvax II which is manufactured in the USA. Of 597 family planning clinic patients screened in 1980-1981, 71 (11.9%) were susceptible to rubella; forty-one subjects were randomly assigned to receive IN or subcutaneous (SC) vaccine. All 20 SC vaccinees, but only 8/21 (38%) IN vaccinees, were successfully immunized. We conclude that standard doses of commercially available RA 27/3 vaccine are insufficient for IN immunization against rubella. Additional study of the dose-response relationship is needed if IN vaccination is to be recommended.