Measles Vaccination in the Presence or Absence of Maternal Measles Antibody: Impact on Child Survival

Background. Measles vaccine (MV) has a greater effect on child survival when administered in early infancy, when maternal antibody may still be present. Methods. To test whether MV has a greater effect on overall survival if given in the presence of maternal measles antibody, we reanalyzed data from 2 previously published randomized trials of a 2-dose schedule with MV given at 4–6 months and at 9 months of age. In both trials antibody levels had been measured before early measles vaccination. Results. In trial I (1993–1995), the mortality rate was 0.0 per 1000 person-years among children vaccinated with MV in the presence of maternal antibody and 32.3 per 1000 person-years without maternal antibody (mortality rate ratio [MRR], 0.0; 95% confidence interval [CI], 0–.52). In trial II (2003–2007), the mortality rate was 4.2 per 1000 person-years among children vaccinated in presence of maternal measles antibody and 14.5 per 1000 person-years without measles antibody (MRR, 0.29; 95% CI, .09–.91). Possible confounding factors did not explain the difference. In a combined analysis, children who had measles antibody detected when they received their first dose of MV at 4–6 months of age had lower mortality than children with no maternal antibody, the MRR being 0.22 (95% CI, .07–.64) between 4–6 months and 5 years. Conclusions. Child mortality in low-income countries may be reduced by vaccinating against measles in the presence of maternal antibody, using a 2-dose schedule with the first dose at 4–6 months (earlier than currently recommended) and a booster dose at 9–12 months of age. Clinical Trials Registration. NCT00168558.