Advanced

BCG scar and positive tuberculin reaction associated with reduced child mortality in West Africa. A non-specific beneficial effect of BCG?

Garly, May-Lill; Martins, Cesario Lourenco; Bale, Carlitos; Balde, Mamadu Aliu; Hedegaard, Kathryn Louise; Gustafson, Per LU ; Lisse, Ida M; Whittle, Hilton C and Aaby, Peter (2003) In Vaccine 21(21-22). p.2782-2790
Abstract
Previous studies have suggested that the bacille Calmette-Guerin (BCG) vaccine may have a non-specific beneficial effect on childhood survival in areas with high mortality. We examined whether BCG-vaccinated children with a BCG scar or a positive tuberculin reaction had better survival than children without such reactions. As part of an ongoing two-dose measles vaccine trial for which children were recruited at 6 months of age, we examined 1813 children for BCG scar at 6 months of age and 813 BCG-vaccinated children were skin-tested for delayed hypersensitivity to tuberculin, tetanus and diphtheria. We found that BCG-vaccinated children with a BCG scar had significantly lower mortality compared with BCG scar-negative children, the... (More)
Previous studies have suggested that the bacille Calmette-Guerin (BCG) vaccine may have a non-specific beneficial effect on childhood survival in areas with high mortality. We examined whether BCG-vaccinated children with a BCG scar or a positive tuberculin reaction had better survival than children without such reactions. As part of an ongoing two-dose measles vaccine trial for which children were recruited at 6 months of age, we examined 1813 children for BCG scar at 6 months of age and 813 BCG-vaccinated children were skin-tested for delayed hypersensitivity to tuberculin, tetanus and diphtheria. We found that BCG-vaccinated children with a BCG scar had significantly lower mortality compared with BCG scar-negative children, the mortality ratio in the first 12 months of follow-up being 0.41 (0.25-0.67). BCG-vaccinated children with a positive tuberculin test had a mortality ratio of 0.45 (0.24-0.85) compared with tuberculin negative children. These results were unchanged by control for potential confounders or using different cut-off points for a tuberculin-positive response. Exclusion of dead children who had HIV antibodies did not modify the estimate (mortality rate (MR)=0.46 (0.23-0.94)). After censoring for tuberculosis (TB) exposure at home, the mortality ratios for having a scar and being tuberculin-positive were 0.46 (0.27-0.79) or 0.42 (0.21-0.84), respectively. Children positive to tetanus or diphtheria in the skin test had the same mortality as children not responding to these vaccine-related antigens. Thus, BCG scar and a positive tuberculin reaction were associated with better survival in early childhood in an area with high mortality. Since nothing similar was found for responders to diphtheria-tetanus-pertussis (DTP) vaccine, and the effect could not be explained by protection against tuberculosis, the effect of BCG vaccination could be due to non-specific immune-stimulation protecting against other infections. (Less)
Please use this url to cite or link to this publication:
author
publishing date
type
Contribution to journal
publication status
published
subject
in
Vaccine
volume
21
issue
21-22
pages
2782 - 2790
publisher
Elsevier
external identifiers
  • pmid:12798618
  • scopus:0038043371
ISSN
1873-2518
DOI
10.1016/S0264-410X(03)00181-6
language
English
LU publication?
no
id
0792d1c5-f436-4d58-a081-b859e23abc84 (old id 1127231)
date added to LUP
2008-06-09 14:18:51
date last changed
2018-02-11 03:29:31
@article{0792d1c5-f436-4d58-a081-b859e23abc84,
  abstract     = {Previous studies have suggested that the bacille Calmette-Guerin (BCG) vaccine may have a non-specific beneficial effect on childhood survival in areas with high mortality. We examined whether BCG-vaccinated children with a BCG scar or a positive tuberculin reaction had better survival than children without such reactions. As part of an ongoing two-dose measles vaccine trial for which children were recruited at 6 months of age, we examined 1813 children for BCG scar at 6 months of age and 813 BCG-vaccinated children were skin-tested for delayed hypersensitivity to tuberculin, tetanus and diphtheria. We found that BCG-vaccinated children with a BCG scar had significantly lower mortality compared with BCG scar-negative children, the mortality ratio in the first 12 months of follow-up being 0.41 (0.25-0.67). BCG-vaccinated children with a positive tuberculin test had a mortality ratio of 0.45 (0.24-0.85) compared with tuberculin negative children. These results were unchanged by control for potential confounders or using different cut-off points for a tuberculin-positive response. Exclusion of dead children who had HIV antibodies did not modify the estimate (mortality rate (MR)=0.46 (0.23-0.94)). After censoring for tuberculosis (TB) exposure at home, the mortality ratios for having a scar and being tuberculin-positive were 0.46 (0.27-0.79) or 0.42 (0.21-0.84), respectively. Children positive to tetanus or diphtheria in the skin test had the same mortality as children not responding to these vaccine-related antigens. Thus, BCG scar and a positive tuberculin reaction were associated with better survival in early childhood in an area with high mortality. Since nothing similar was found for responders to diphtheria-tetanus-pertussis (DTP) vaccine, and the effect could not be explained by protection against tuberculosis, the effect of BCG vaccination could be due to non-specific immune-stimulation protecting against other infections.},
  author       = {Garly, May-Lill and Martins, Cesario Lourenco and Bale, Carlitos and Balde, Mamadu Aliu and Hedegaard, Kathryn Louise and Gustafson, Per and Lisse, Ida M and Whittle, Hilton C and Aaby, Peter},
  issn         = {1873-2518},
  language     = {eng},
  number       = {21-22},
  pages        = {2782--2790},
  publisher    = {Elsevier},
  series       = {Vaccine},
  title        = {BCG scar and positive tuberculin reaction associated with reduced child mortality in West Africa. A non-specific beneficial effect of BCG?},
  url          = {http://dx.doi.org/10.1016/S0264-410X(03)00181-6},
  volume       = {21},
  year         = {2003},
}