Abstract
OBJECTIVES: To determine whether BCG vaccination protects against Mycobacterium tuberculosis infection as assessed by interferon γ release assays (IGRA) in children.
DESIGN: Systematic review and meta-analysis. Searches of electronic databases 1950 to November 2013, checking of reference lists, hand searching of journals, and contact with experts.
SETTING: Community congregate settings and households.
INCLUSION CRITERIA: Vaccinated and unvaccinated children aged under 16 with known recent exposure to patients with pulmonary tuberculosis. Children were screened for infection with M tuberculosis with interferon γ release assays.
DATA EXTRACTION: Study results relating to diagnostic accuracy were extracted and risk estimates were combined with random effects meta-analysis.
RESULTS: The primary analysis included 14 studies and 3855 participants. The estimated overall risk ratio was 0.81 (95% confidence interval 0.71 to 0.92), indicating a protective efficacy of 19% against infection among vaccinated children after exposure compared with unvaccinated children. The observed protection was similar when estimated with the two types of interferon γ release assays (ELISpot or QuantiFERON). Restriction of the analysis to the six studies (n=1745) with information on progression to active tuberculosis at the time of screening showed protection against infection of 27% (risk ratio 0.73, 0.61 to 0.87) compared with 71% (0.29, 0.15 to 0.58) against active tuberculosis. Among those infected, protection against progression to disease was 58% (0.42, 0.23 to 0.77).
CONCLUSIONS: BCG protects against M tuberculosis infection as well as progression from infection to disease.Trial registration PROSPERO registration No CRD42011001698 (www.crd.york.ac.uk/prospero/).
Original language | English |
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Pages (from-to) | g4643 |
Journal | BMJ (Clinical research ed.) |
Volume | 349 |
DOIs | |
Publication status | Published - 5 Aug 2014 |
Keywords
- Adolescent
- BCG Vaccine
- Child
- Child, Preschool
- Humans
- Infant
- Interferon-gamma/blood
- Interferon-gamma Release Tests
- Mycobacterium tuberculosis/immunology
- Tuberculosis/prevention & control