title: Variation of growth in the production of the BCG vaccine and the association with the immune response. An observational study within a randomised trial.
abstract: BACKGROUND
  Bacille Calmette-Guérin (BCG) vaccine has beneficial non-specific effects on overall survival. After BCG vaccination, positive PPD response and scar formation are associated with increased survival. During a trial randomising low-birth-weight neonates to BCG at birth or the usual delayed BCG, the manufacturer of the BCG vaccine experienced a period with relatively slow growth rate of the BCG. We investigated the association between growth rate of BCG when manufacturing the vaccine and its capability to induce immune responses in vivo and in vitro.
  
  
  METHODS
  1633 neonates were randomised to BCG at birth and examined for scar at 12 months; a subgroup was tested for PPD response at 2 and 6 months. The BCG batches from the Slow growth period were compared with the precedent and subsequent Normal growth batches with regard to prevalence and size of BCG scar and PPD response. We also tested the effect of batches on in vitro cytokine responses.
  
  
  RESULTS
  At 12 months, the Slow growth batches were associated with higher BCG scar prevalence (98.2%) than the precedent batches (92.3%, p=0.01) but the prevalence remained high after return to normal growth (98.8%, p=0.52). The Slow growth batches were associated with larger scar size (5.0mm) than precedent (4.4mm, p<0.01) and subsequent batches (4.8mm, p=0.03). Compared with Normal growth batches, the Slow growth batches were associated with a higher prevalence of positive PPD responses, and among PPD positive children, a larger PPD reaction (geometric mean ratio: 1.40 (1.20-1.63)) at 2 months. In response to secondary heterologous stimulation, monocytes primed with Slow growth batches induced higher IL-6 (p=0.03) and TNF-α responses (p=0.03) compared with Normal growth batches.
  
  
  CONCLUSIONS
  The study indicates that variations in the production of BCG vaccine may influence important immunological effects of the vaccine.
  
  
  BACKGROUND
  clinicaltrials.gov (NCT00625482).
authors.affiliation: Research Center for Vitamins & Vaccines (CVIVA), Bandim Health Project, Statens Serum Institut, DK-2300 Copenhagen S, Denmark; Projécto de Saúde Bandim, INDEPTH Network, Codex 1004, Bissau, Guinea-Bissau. Electronic address: s.biering@bandim.org.
authors.forename: Sofie
authors.initials: S
authors.lastname: Biering-Sørensen
authors.affiliation: Research Center for Vitamins & Vaccines (CVIVA), Bandim Health Project, Statens Serum Institut, DK-2300 Copenhagen S, Denmark; Projécto de Saúde Bandim, INDEPTH Network, Codex 1004, Bissau, Guinea-Bissau; Department of Cardiovascular and Renal Research, Faculty of Health Sciences, University of Southern Denmark, DK-5000 Odense, Denmark.
authors.forename: Kristoffer Jarlov
authors.initials: KJ
authors.lastname: Jensen
authors.affiliation: Bacterial Vaccine Department, Statens Serum Institut, DK-2300 Copenhagen S, Denmark.
authors.forename: Susanne Havn
authors.initials: SH
authors.lastname: Aamand
authors.affiliation: Department of Internal Medicine, Radboud University Medical Center, 6525GA Nijmegen, The Netherlands.
authors.forename: Bastiaan
authors.initials: B
authors.lastname: Blok
authors.affiliation: Research Center for Vitamins & Vaccines (CVIVA), Bandim Health Project, Statens Serum Institut, DK-2300 Copenhagen S, Denmark; Projécto de Saúde Bandim, INDEPTH Network, Codex 1004, Bissau, Guinea-Bissau.
authors.forename: Andreas
authors.initials: A
authors.lastname: Andersen
authors.affiliation: Projécto de Saúde Bandim, INDEPTH Network, Codex 1004, Bissau, Guinea-Bissau.
authors.forename: Ivan
authors.initials: I
authors.lastname: Monteiro
authors.affiliation: Department of Internal Medicine, Radboud University Medical Center, 6525GA Nijmegen, The Netherlands.
authors.forename: Mihai G
authors.initials: MG
authors.lastname: Netea
authors.affiliation: Projécto de Saúde Bandim, INDEPTH Network, Codex 1004, Bissau, Guinea-Bissau.
authors.forename: Peter
authors.initials: P
authors.lastname: Aaby
authors.affiliation: Research Center for Vitamins & Vaccines (CVIVA), Bandim Health Project, Statens Serum Institut, DK-2300 Copenhagen S, Denmark; Odense Patient Data Explorative Network, Institute of Clinical Research, University of Southern Denmark/Odense University Hospital, DK-5000 Odense C, Denmark.
authors.forename: Christine Stabell
authors.initials: CS
authors.lastname: Benn
authors.affiliation: Vaccine Quality Control, Statens Serum Institut, DK-2300 Copenhagen S, Denmark.
authors.forename: Kaare Robert
authors.initials: KR
authors.lastname: Hasløv
mesh_terms: D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D001500:BCG Vaccine / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology / Q000592:standards; D016207:Cytokines / Q000276:immunology; D005500:Follow-Up Studies; D007230:Infant, Low Birth Weight / Q000276:immunology; D016753:Interleukin-10 / Q000276:immunology; D015850:Interleukin-6 / Q000276:immunology; D009000:Monocytes / Q000276:immunology; D009163:Mycobacterium bovis / Q000254:growth & development / Q000276:immunology; D013997:Time Factors; D014374:Tuberculin Test; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology; D016032:Randomized Controlled Trials as Topic
chemical_list: D001500:BCG Vaccine; D016207:Cytokines; D016753:Interleukin-10; D015850:Interleukin-6; C439524:TNF protein, human; D014409:Tumor Necrosis Factor-alpha
keywords: Bacillus Calmette–Guérin; Cytokine; Heterologous immunity; Immunogenicity; Infant; Tuberculin PPD; Vaccine production