title: Acute lower respiratory infection among Bacille Calmette-Guérin (BCG)-vaccinated children.
abstract: OBJECTIVE
  To determine whether Bacille Calmette-Guerin (BCG) vaccination is linked to the risk of acute lower respiratory infection (ALRI) among children <5 years of age.
  
  
  METHODS
  Data from Macro International Demographic and Health Surveys and United Nations Children's Fund Multiple Indicator Cluster Surveys were used to identify a primary cohort of 58,021 children in 19 countries (2005-2010) and a secondary cohort of 93,301 children in 18 countries (2000-2007). Information was collected by trained interviewers during home visits using standardized questionnaires, review of vaccination health cards, and measurement of health indicators.
  
  
  RESULTS
  BCG vaccination was associated with a 17% to 37% risk reduction for suspected ALRI in both cohorts. The only vaccine or vitamin supplement to modify the effect of BCG was diphtheria-tetanus-pertussis (DTP; P < .001). The order in which the vaccines were first received was central to this phenomena (BCG before DTP, adjusted/propensity score-weighted relative risk [apRR]: 0.79, 95% confidence interval [CI]: 0.70-0.89; BCG with DTP, apRR: 0.82, 95% CI: 0.71-0.94; and BCG after DTP, apRR: 1.00, 95% CI: 0.87-1.13) but not number of DTP doses received. Other modifiers included vaccine strain used in immunization programs, chlorinating drinking water, using wood-burning fuel cook stoves, and owning livestock.
  
  
  CONCLUSIONS
  Children vaccinated with BCG had a significantly lower risk of suspected ALRI. Clarification is needed as to whether this is due to reductions in the underlying risk of tuberculosis or ALRI per se.
authors.affiliation: Department of International Health, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe St, Baltimore, MD 21205. mhollmd@jhsph.edu.
authors.forename: Maria-Graciela
authors.initials: MG
authors.lastname: Hollm-Delgado
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Stuart
authors.forename: Robert E
authors.initials: RE
authors.lastname: Black
mesh_terms: D000208:Acute Disease; D001500:BCG Vaccine; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D014943:Global Health; D006306:Health Surveys; D006801:Humans; D007223:Infant; D008297:Male; D012044:Regression Analysis; D012141:Respiratory Tract Infections / Q000517:prevention & control*; D012306:Risk; D016896:Treatment Outcome; D014376:Tuberculosis / Q000517:prevention & control
chemical_list: D001500:BCG Vaccine
keywords: Bacille Calmette-Guerin (BCG) vaccine; childhood immunization; developing countries; diphtheria-tetanus-pertussis (DTP) vaccine; respiratory tract infection