Immune response to measles vaccine in Peruvian children

To evaluate the immune response in Peruvian children following measles vaccination. Fifty-five Peruvian children received Schwarz measles vaccine (about 10(3) plaque forming units) at about 9 months of age. Blood samples were taken before vaccination, then twice after vaccination: one sample at between 1 and 4 weeks after vaccination and the final sample 3 months post vaccination for evaluation of immune cell phenotype and lymphoproliferative responses to measles and non-measles antigens. Measles-specific antibodies were measured by plaque reduction neutralization. The humoral response developed rapidly after vaccination; only 4 of the 55 children (7%) had plaque reduction neutralization titres