title: BCG revaccination does not protect against leprosy in the Brazilian Amazon: a cluster randomised trial.
abstract: BACKGROUND
  Although BCG has been found to impart protection against leprosy in many populations, the utility of repeat or booster BCG vaccinations is still unclear. When a policy of giving a second BCG dose to school children in Brazil was introduced, a trial was conducted to assess its impact against tuberculosis, and a leprosy component was then undertaken in parallel.
  
  
  OBJECTIVE
  to estimate the protection against leprosy imparted by a second dose of BCG given to schoolchildren.
  
  
  RESULTS
  This is a cluster randomised community trial, with 6 years and 8 months of follow-up.
  
  
  METHODS
  City of Manaus, Amazon region, a leprosy-endemic area in Brazil.
  
  
  METHODS
  99,770 school children with neonatal BCG (aged 7-14 years at baseline), of whom 42,662 were in the intervention arm (revaccination).
  
  
  METHODS
  BCG given by intradermal injection.
  
  
  RESULTS
  Leprosy (all clinical forms).
  
  
  RESULTS
  The incidence rate ratio of leprosy in the intervention over the control arm within the follow-up, in schoolchildren with neonatal BCG, controlled for potential confounders and adjusted for clustering, was 0.99 (95% confidence interval: 0.68 to 1.45).
  
  
  CONCLUSIONS
  There was no evidence of protection conferred by the second dose of BCG vaccination in school children against leprosy during the trial follow-up. These results point to a need to consider the effectiveness of the current policy of BCG vaccination of contacts of leprosy cases in Brazilian Amazon region.
authors.affiliation: Instituto de Saúde Coletiva, Universidade Federal da Bahia, State of Bahia, Brazil. cunhatmt@hotmail.com
authors.forename: Sérgio S
authors.initials: SS
authors.lastname: Cunha
authors.forename: Neal
authors.initials: N
authors.lastname: Alexander
authors.forename: Mauricio L
authors.initials: ML
authors.lastname: Barreto
authors.forename: Emilia S
authors.initials: ES
authors.lastname: Pereira
authors.forename: Inês
authors.initials: I
authors.lastname: Dourado
authors.forename: Maria de Fátima
authors.initials: Mde F
authors.lastname: Maroja
authors.forename: Yury
authors.initials: Y
authors.lastname: Ichihara
authors.forename: Silvana
authors.initials: S
authors.lastname: Brito
authors.forename: Susan
authors.initials: S
authors.lastname: Pereira
authors.forename: Laura C
authors.initials: LC
authors.lastname: Rodrigues
mesh_terms: D000293:Adolescent; D001500:BCG Vaccine / Q000008:administration & dosage*; D001938:Brazil / Q000453:epidemiology; D002648:Child; D005260:Female; D006801:Humans; D015994:Incidence; D007918:Leprosy / Q000453:epidemiology / Q000276:immunology / Q000517:prevention & control*; D008297:Male; D014611:Vaccination
chemical_list: D001500:BCG Vaccine