Evaluation of non-specific effects of infant immunizations on early infant mortality in a southern Indian population
The aim of this study was to assess the relationship between receipt of routine childhood immunizations and infant mortality before 6 months of age. Methods
This was an observational study of 10 274 infants, in a randomized trial of vitamin A supplementation, who received the study dose and survived to at least 1 week of age. The primary outcome was mortality before 6 months of age, analysed in Cox regression models as a function of vaccine receipt and gender. Results
Receipt of Bacille Calmette Guerin (BCG) or diphtheria, tetanus, polio (DTP) vaccine was associated with significant reductions of one-half to two-thirds of mortality hazards; among girls, those who received both BCG and DTP experienced higher mortality than those who received only one of the two vaccines (hazards ratio 2.4; 95% confidence interval 1.2–5.0). Conclusion
The reduced mortality rate associated with receipt of BCG or DTP may be due to both biological and selection factors; the analyses regarding the combined effect of these vaccines and gender need to be replicated in other settings.
Document Type: Research Article
Affiliations: 1: Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA 2: Aravind Centre for Women, Children and Community Health, Madurai, Tamil Nadu, India 3: Lions-Aravind Institute for Community Ophthalmology, Madurai, Tamil Nadu, India
Publication date: October 1, 2005