Prevalence of Maternal Measles Antibody and Its Associated Factors among Infants in Coastal Karnataka, India

BACKGROUND: The current recommendation in India to commence first dose of measles immunization is at 9 months of age. The effectiveness of measles vaccination is greatly impacted by the level of maternal measles antibody (MMA) during infancy. OBJECTIVES: To find the prevalence of MMA and to study the maternal and infant factors associated with persistence of MMA among the infants in a Indian rural community. METHODOLOGY: Dried blood spot sample was collected before vaccination among infants aged 9 months and above when they came for first dose of measles vaccine to assess measles-specific maternal IgG antibody titers by enzyme immunoassay. Maternal and child factors influencing persistence of MMA were collected by interviewing the mothers. Association between various factors affecting seropositivity was tested using univariate logistic regression analysis and strength of association is reported as risk ratio with 95% confidence interval. RESULTS: Based on the qualitative estimation among all the recruited children (250) in the study, 4 (1.6%) infants showed the presence of MMA whereas 25 (10%) of children had MMA on quantitative estimation. The effect of maternal factors, child nutrition, and sociodemographic factors on the presence of MMA was not found to be statistically significant. CONCLUSION: The prevalence of persistent MMA (IgG titer ≥200 mIU/ml) among the infants aged 9–12 months was 10%. The choice of vaccinating infants at the end of 9 months for the first dose of measles vaccine is justified as the remaining (90%) of infants were susceptible for measles infection at this age.