ANTIBODY PERSISTENCE IN GAMBIAN CHILDREN AFTER HIGH-DOSE EDMONSTON-ZAGREB MEASLES-VACCINE

Measles antibody concentrations in Gambian children immunised at 4 months of age with a high-dose Edmonston-Zagreb (EZ) measles vaccine or at 9 months with conventional Schwarz vaccine were measured 5 months after vaccination, and at 18 and 36 months of age. Schwarz vaccinees produced, on average, a 2-4-fold higher concentration of measles haemagglutinin inhibiting (HAI) antibody than EZ vaccinees, but at 36 months of age 82 of 93 (88%) EZ vaccinees and 83 of 87 (95%) Schwarz vaccinees had measles plaque-neutralising antibody concentrations above the assumed protective level of 200 mlU/ml (p>0·1). HAI antibody concentrations 5 months after vaccination were inversely related to the presence of maternal antibody at vaccination, but above protective levels; at 18 and 36 months of age there was no relation to antibody concentration at vaccination, and decay of HAI antibody between 18 and 36 months of age was similar for EZ and Schwarz vaccinees. © 1990.