Non-specific effects of vaccination on child survival? A prospective study in Senegal

OBJECTIVES Several studies have shown an association between vaccination and child mortality in developing countries. The present paper examines this issue using data from a Senegalese rural area which has been monitored from 1983 to the present. METHODS We analysed two birth cohorts, comprising 7796 and 3573 persons who had received either BCG and DTP (diphtheria-tetanus-pertussis) simultaneously or neither of these vaccines, and who had been followed from birth to 2 years of age. The association between vaccinations and mortality was assessed by Cox proportional hazards model. RESULTS Mortality ratios for recipients of the BCG/DTP combination were 0.59 (95% CI: 0.46-0.74) for the first cohort and 0.70 (0.50-0.97) for the second cohort. Mortality ratios for measles vaccine recipients were 0.98 (0.75-1.27) for the first cohort and 0.87 (0.57-1.30) for the second cohort. CONCLUSIONS The BCG/DTP combination was associated with a reduction in mortality whereas measles vaccination was not associated with mortality.