Risk factors for altered measles vaccine response in a population of Jamaican children

Measles remains a major cause of childhood death accounting for nearly one million deaths in 1990. Public health strategists continue to work towards eliminating this disease but require a better understanding of the immune response to natural and vaccine-induced infection. An analysis of several factors that have been suggested to affect vaccine response was undertaken in this study of 290 Jamaican mothers and their children. The factors of interest included maternal HTLV-I infection, changing levels of maternal measles antibody, gender, vitamin A levels and illness at the time of vaccination. Additionally, comparisons of a commercial measles antibody ELISA and a newly developed glycoprotein specific ELISA were made to determine if there was any improved testing accuracy with the new assay.; Blood samples from mothers and their children were tested using both antibody assays. Children had a pre-vaccine sample and two post-vaccine samples (early and late) tested for measles antibody levels. Seroconversion rates and mean antibody levels were analyzed for each hypothesized risk factor.; The vaccinated children had a high rate of seroconversion. Maternal HTLV-I infection, mother's birth cohort, gender, vitamin A level, and illness at the time of vaccination were not associated with an altered response to measles vaccination. Seroconversion rates and antibody levels were not significantly different for any of the factors of interest. The commercial ELISA did not appear to measure low levels of antibody as well as the antibody-specific assay, although, the two tests were generally highly correlated.; This study supports the assertions of many that the measles vaccine is very effective at inducing a long lasting immune response in a variety of children. Clinicians with concerns about vaccinating children born to HTLV-I infected mothers or who have symptoms of a minor illness do not need to postpone this important immunization. The lack of an association between vitamin A and vaccine response was perhaps this study's most interesting finding and suggests that vitamin A supplementation may not be a necessary practice for assuring measles vaccine response. This analysis should provide some helpful information for those working to eliminate measles as they plan future vaccine programs.