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

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.

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.

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.

The BCG/DTP combination was associated with a reduction in mortality whereas measles vaccination was not associated with mortality.