Experience with live rubella virus vaccine combined with live vaccines against measles and mumps.

Vaccination of pre-school children in the 1-7-years age-group for the specific prophylaxis of mumps and rubella is often difficult to arrange because of the already large number of inoculations given to these children. Combined vaccines to protect against measles, mumps and rubella should therefore be a valuable development. The existence of effective live vaccines for each of these 3 diseases makes possible the production of a single preparation suitable for subcutaneous inoculation.Tests on vaccine strains of measles (Leningrad-16), mumps (Leningrad-3) and rubella (Leningrad-8) viruses in various combinations have established that divalent or trivalent vaccines remain clinically harmless, highly immunogenic and epidemiologically effective. Single subcutaneous administrations of live measles vaccine combined with mumps or rubella vaccines or both, when given to children aged 1-8 years, brough about a high percentage of serological conversions and an increase in antibodies to a level comparable with that achieved with the corresponding monovalent vaccines. Morbidity from the 3 diseases was reduced among those vaccinated with the trivalent vaccine by 10 or more times, i.e., by about the same factor as when monovalent or divalent vaccines were used.