Measles HI-antibody levels in Lagos children, Nigeria: a follow-up study to resurgence of measles in Lagos metropolis.

A total of 138 children aged between 0-36 months were bled and screened for measles haemagglutination inhibiting (HI)-antibody. Twenty seven children were from age group (0-4) months with 16 (59.3%) seropositive while, 67 and 44 were bled in the group (5-9) and > or = 12 months with 29 (43.3%) and 31 (70.5%) sero positive sera respectively. The distribution of the antibody titre pattern among various age groups suggest vaccination against measles should be at age 9 month. The antibody titres pattern of seroconverted vaccinees also showed that the vaccine administered at our study centre were potent enough to elicit good and protective immune response in vaccinees when given at age 9 month. Our study agrees with the current policy of vaccinating children against measles at age 9 months in Nigeria and should therefore be continued. Based on observations in this study, we suggest; continued administration of the Edmonston-Zagreb strain of measle vaccine currently-in-use in Nigeria, mother's breast-feeding of children for a longer period before the apporpriate age for vaccination, and the possible administration of Vitamin A-a potent immune enhancer, as a supplement during immunization programmes in Nigeria. The introduction of a booster dose of measles vaccine at elementary school age in order to care for the residual unvaccinated children may be a good strategy for measles eradication necessary to be considered in Nigeria and might probably forestall instances of measles outbreaks in children during their second year in school.