Immune response to measles vaccine in 6 month old infants in Papua New Guinea

Abstract

Objective : To assess the efficacy of the current measles immunization schedule in Papua New Guinea, which is to give the first dose at 6 months of age and the second at 9 months. Methods : Humoral immune response study of 140 Papua New Guinean infants at 6 months of age, measuring measles IgG antibodies by enzyme immunoassay before and 85 days after the 6-month dose of measles vaccine. Results : After vaccination at 6 months, 35.7% of infants developed a level of measles antibodies consistent with protection (IgG >330 IU/ml); 17.7% had an antibody response (150-330 IU/ml) that is likely to afford some protection; 46.8% had no detectable antibody response (IgG <150 IU/ml). Among 53 infants w..