title: What does tuberculin reactivity after bacille Calmette-Guérin vaccination tell us?
abstract: The effect of bacille Calmette-Guérin (BCG) vaccination on tuberculin reactivity is briefly reviewed. BCG vaccination will almost invariably result in tuberculin conversion with a positive tuberculin skin test developing 4-8 weeks after vaccination. However, these tuberculin reactions will wane-rapidly in all individuals who receive the vaccine in the neonatal period and more slowly in those who are vaccinated at an older age such as during the primary-school years. Of BCG vaccine recipients whose initial tuberculin skin test is negative, 10%-25% will have a positive tuberculin skin test if they are retested within 1-4 weeks-the so-called "booster phenomenon. " There is no relationship between tuberculin reactivity after BCG vaccination and the protective efficacy of the vaccine against development of active tuberculosis. Therefore, the ideal BCG vaccine would produce a scar at the site of injection to identify individuals who have been vaccinated but would have no effect on tuberculin reactivity.
authors.affiliation: Department of Medicine, Montreal Chest Institute, McGill University, Montreal, Quebec, Canada. menzies@meakins.lan.mcgill.ca
authors.forename: D
authors.initials: D
authors.lastname: Menzies
mesh_terms: D000293:Adolescent; D001500:BCG Vaccine / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D014374:Tuberculin Test; D014376:Tuberculosis / Q000517:prevention & control*; D014611:Vaccination
chemical_list: D001500:BCG Vaccine