Protection by BCG Vaccine Against Tuberculosis: A Systematic Review of Randomized Controlled Trials
Clinical Infectious Diseases·
- DOI
- 10.1093/cid/cit790
- PMID
- 24336911
- PMCID
- —
- OpenAlex
- W2010318115
- Study type
- Systematic review
- Publisher
- Oxford University Press (OUP)
- Article type
- journal-article
- Integrity
- current
Why this research matters now
Recognizing how baseline exposure status and methodological choices affect outcome measurements may guide the planning and evaluation of future immunization initiatives.
Structured evidence summary
Research question
How do trial design features and participant characteristics influence the measured effectiveness of the BCG immunization against tuberculosis?
Study design
The authors performed a systematic review and meta-analysis of randomized controlled trials, incorporating meta-regression techniques to assess how specific trial attributes modify reported outcomes.
Population and setting
Data were aggregated from eighteen studies evaluating pulmonary disease and six examining severe disseminated or central nervous system forms, covering diverse geographic locations and age cohorts.
Main findings
Reported protection levels fluctuated significantly depending on screening rigor, participant age, and geographic latitude. Highest efficacy estimates occurred in infants and subjects who received thorough testing to exclude previous bacterial exposure. Measured benefits also increased in regions farther from the equator and under stricter diagnostic conditions, whereas vaccine strain variations showed no consistent relationship with outcomes.
Public-health relevance
Recognizing how baseline exposure status and methodological choices affect outcome measurements may guide the planning and evaluation of future immunization initiatives.
Important limitations
Statistical associations between trial characteristics and efficacy diminished when evaluated simultaneously within multivariable frameworks, indicating potential overlapping influences among study variables.
GIDS interpretation
This synthesis consolidates historical trial data to establish a reference framework for understanding variable reporting patterns in vaccine literature, supporting academic tracking without referencing active monitoring systems.
Related GIDS surveillance
Literature context does not validate, explain, or change a surveillance signal. Exact and contextual relationships are shown separately.
Evidence relationships
This article has 11 auditable classifier relationships to diseases, places, topics, and study design.