Evaluation of non-specific effects of infant immunizations on early infant mortality in a southern Indian population.
OBJECTIVE
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).


CONCLUSIONS
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.
Moulton
Lawrence H
LH
Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA. lmoulton@jhsph.edu
Rahmathullah
Lakshmi
L
Halsey
Neal A
NA
Thulasiraj
R D
RD
Katz
Joanne
J
Tielsch
James M
JM
D001500:BCG Vaccine / Q000008:administration & dosage; D019587:Dietary Supplements; D015721:Diphtheria-Tetanus-Pertussis Vaccine / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007114:Immunization; D007115:Immunization Schedule; D007194:India / Q000453:epidemiology; D007223:Infant; D007226:Infant Mortality; D007231:Infant, Newborn; D008297:Male; D011055:Poliovirus Vaccine, Oral / Q000008:administration & dosage; D017678:Sex Distribution; D012959:Socioeconomic Factors; D016019:Survival Analysis; D014801:Vitamin A / Q000008:administration & dosage
D001500:BCG Vaccine; D015721:Diphtheria-Tetanus-Pertussis Vaccine; D011055:Poliovirus Vaccine, Oral; D014801:Vitamin A