title: Delaying BCG vaccination from birth to 10 weeks of age may result in an enhanced memory CD4 T cell response.
abstract: BACKGROUND
  In most tuberculosis (TB) endemic countries, bacillus Calmette-Guérin (BCG) is usually given around birth to prevent severe TB in infants. The neonatal immune system is immature. Our hypothesis was that delaying BCG vaccination from birth to 10 weeks of age would enhance the vaccine-induced immune response.
  
  
  METHODS
  In a randomized clinical trial, BCG was administered intradermally either at birth (n=25) or at 10 weeks of age (n=21). Ten weeks after vaccination, and at 1 year of age, vaccine-specific CD4 and CD8 T cell responses were measured with a whole blood intracellular cytokine assay.
  
  
  RESULTS
  Infants who received delayed BCG vaccination demonstrated higher frequencies of BCG-specific CD4 T cells, particularly polyfunctional T cells co-expressing IFN-gamma, TNF-alpha and IL-2, and most strikingly at 1 year of age.
  
  
  CONCLUSIONS
  Delaying BCG vaccination from birth to 10 weeks of age enhances the quantitative and qualitative BCG-specific T cell response, when measured at 1 year of age.
authors.affiliation: South African Tuberculosis Vaccine Initiative (SATVI), Institute of Infectious Diseases and Molecular Medicine and School of Child and Adolescent Health, University of Cape Town, Cape Town, South Africa.
authors.forename: Benjamin M N
authors.initials: BM
authors.lastname: Kagina
authors.forename: Brian
authors.initials: B
authors.lastname: Abel
authors.forename: Mark
authors.initials: M
authors.lastname: Bowmaker
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Scriba
authors.forename: Sebastian
authors.initials: S
authors.lastname: Gelderbloem
authors.forename: Erica
authors.initials: E
authors.lastname: Smit
authors.forename: Mzwandile
authors.initials: M
authors.lastname: Erasmus
authors.forename: Nonhlanhla
authors.initials: N
authors.lastname: Nene
authors.forename: Gerhard
authors.initials: G
authors.lastname: Walzl
authors.forename: Gillian
authors.initials: G
authors.lastname: Black
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Hussey
authors.forename: Anneke C
authors.initials: AC
authors.lastname: Hesseling
authors.forename: Willem A
authors.initials: WA
authors.lastname: Hanekom
mesh_terms: D001500:BCG Vaccine / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D006801:Humans; D007115:Immunization Schedule; D007156:Immunologic Memory / Q000276:immunology*; D007223:Infant; D007231:Infant, Newborn; D007371:Interferon-gamma / Q000276:immunology; D007376:Interleukin-2 / Q000276:immunology; D014376:Tuberculosis / Q000276:immunology / Q000517:prevention & control*; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology; D014611:Vaccination
chemical_list: D001500:BCG Vaccine; D007376:Interleukin-2; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma