Laure F. Pittet (Switzerland)
Hôpitaux Universitaires de Genève Pediatrics, Infectious Diseases UnitPresenter of 3 Presentations
SCAR FORMATION FOLLOWING INFANT IMMUNISATION WITH BACILLE CALMETTE-GUÉRIN IS ASSOCIATED WITH ENHANCED MYCOBACTERIUM-SPECIFIC T-CELL RESPONSES (ID 72)
Abstract
Background
Limited evidence suggests that scar formation after bacille Calmette-Guérin (BCG) immunisation is associated with lower all-cause mortality but does not correlate with protection against tuberculosis. The aim of this post-hoc analysis was to evaluate the association between BCG scar characteristics and the mycobacterial-specific immune response.
Methods
208 infants in Australia were randomised to receive one of three BCG vaccine strains at birth (BCG-Denmark, n=53; BCG-Japan, n=55; or BCG-Russia, n=56) or at 2 months of age (BCG-Denmark, n=44). The size and characteristics of BCG scars were assessed 10 weeks after immunisation. At the same time point, intracellular cytokine secretion (IFNg, IL-2 and TNF) in whole blood assays following in-vitro stimulation with M. tuberculosis, M. ulcerans, PPD and BCG was determined using multi-colour flow cytometry. The relationship between BCG scar characteristics and immunological responses was analysed.
Results
Proportions of single, double, and triple antigen-specific cytokine-producing CD4+ T-cells were significantly higher in children who developed a BCG scar compared to those without a scar. The magnitude of the immune response correlated with the size and characteristic of the BCG scar (Figure), even after adjusting for BCG vaccine strain and timing of immunisation in a mixed model analysis.
Conclusions
BCG scar formation is associated with higher mycobacteria-specific T-cell responses. As T-cell responses are important in the immune response against TB, the relationship between BCG scar formation and protection against TB should be explored further.
Clinical Trial Registration
Australian clinical trials registration number: ACTRN12608000227392
NEONATAL BCG VACCINATION REDUCES THE RISK OF ECZEMA IN PREDISPOSED INFANTS – RESULTS FROM THE MIS BAIR RANDOMISED CONTROLLED TRIAL (ID 148)
Abstract
Background
Bacille Calmette-Guérin (BCG) vaccine could play a role in counteracting the rising prevalence of atopic diseases through its beneficial off-target effects. One aim of the MIS BAIR trial was to determine whether neonatal BCG vaccination reduces the incidence of eczema in the first year of life.
Methods
In this randomised controlled trial, the incidence and severity of eczema in the first 12 months of life was determined with 3-monthly questionnaires using the UK diagnostic tool and POEM score, respectively. Eczema was also assessed at a 12-month clinic visit using SCORAD.
Results
1272 infants were randomised to receive BCG-Denmark (median 1.5 days of life; IQR 0.9 to 2.5) or no BCG. The incidence of eczema in the first 12 months of life was lower in the BCG group (32.2%) compared with controls (36.6%) (risk difference (RD) -4.3%,95%CI -9.9% to 1.3%; multiple imputation model), resulting in a number needed to treat (NNT) of 23. Compared with controls, infants in the BCG group were less likely to have active eczema lesions at the 12-month visit (15.7% vs.19.2%;RD -3.5%,95%CI -8.0% to 1.0%), to use topical steroids (35.7% vs.39.0%;RD -3.3%,95%CI -9.2 to 2.7), and to have severe eczema scores (7.3% vs.10.2%;RD -3.0%,95%CI -8.8% to 2.7%), especially in the 3-month questionnaire (4.9% vs.15.9%;RD -11.0%,95%CI -23.7% to 1.6%). In high-risk infants (two atopic parents, n=344), the incidence of eczema was lower in the BCG group (35.3%) compared with controls (46.8%) (RD -11.5%,95%CI -21.9% to -1.2%) with a NNT of 8.7 (95%CI 4.6 to 83.3).
Conclusions
A single dose of BCG-Denmark soon after birth reduced the incidence of eczema, especially in infants with two atopic parents. There is insufficient evidence to recommend neonatal BCG vaccination for the general prevention of eczema.
Clinical Trial Registration
ClinicalTrial.gov: NCT01906853.
Pro and Con decolonisation (ID 211)
Moderator of 2 Sessions
