Immune response to Edmonston-Zagreb measles virus strain in monovalent and combined MMR vaccine.

The live Edmonston-Zagreb measles vaccine is currently produced either on chick-embryo fibroblasts (CEF) or on human diploid cells (HDC). Its stability meets the WHO requirements. Since the vaccine licensure in 1967 the Edmonston-Zagreb measles virus strain has been administered to over 20 million vaccinees either as a monovalent vaccine or as a component of the combined MR, MMR and MM vaccines. Immunogenicity studies have shown the persistence of the elicited HI antibody for a minimum of 16 years. In children aged 13-17 months a greater than 95% seroconversion was recorded after subcutaneous administration both CEF and HDC vaccines. The vaccine has also been shown to be highly immunogenic when administered intranasally. In 6-12 month old infants the Edmonston-Zagreb monovalent vaccine elicited a 100% HI antibody response after both s.c. and i.n. administration. The GMT of antibody 42 days after vaccination was significantly higher in those given HDC vaccine, regardless of the age of the vaccinees or the route of immunization.