title: Earlier infantile immune maturation is related to higher DTP vaccine responses in children.
abstract: There are large inter-individual variations in vaccine-specific antibody responses in children. We sought to investigate whether early-life environmental factors and/or adaptive immune maturation were related to diphtheria-tetanus-pertussis (DTP) vaccine-specific antibody levels at 18 months of age. In the prospective FARMFLORA birth-cohort, including both farming and non-farming families, children were immunized with DTP vaccine at 3, 5 and 12 months of age. DTP vaccine-induced antibody levels were measured in plasma at 18 months of age. Infants' blood samples obtained at birth, 3-5 days, 4, 18 and 36 months and at 8 years of age were analyzed for total CD4(+) T- and B-cell counts, proportions of naïve and memory T and B cells, and fractions of putative regulatory T cells by flow cytometry. Multivariate factor analysis was used to examine associations between immune variables and vaccine responses. The most apparent multivariate pattern was that higher anti-DTP antibody titers at 18 months of age were associated with lower infantile total counts of T and B cells in the blood. Furthermore, lower infantile total T- and B-cell blood counts were associated with higher proportions of circulating CD45RO(+) memory T cells and to lower proportions of α4β7(+) naïve T cells later in childhood. The multivariate findings were corroborated in univariate correlation analyses. Sex, delivery mode and dairy farm exposure were unrelated to the magnitude of DTP-specific antibody responses. Our results thus suggest that children with a more mature/activated infantile adaptive immunity respond with higher vaccine-induced anti-DTP antibody levels at 18 months of age.
authors.affiliation: Department of Rheumatology and Inflammation Research, Institute of Medicine, The Sahlgrenska Academy, University of Gothenburg , Gothenburg, Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Strömbeck
authors.affiliation: Department of Rheumatology and Inflammation Research, Institute of Medicine, The Sahlgrenska Academy, University of Gothenburg , Gothenburg, Sweden.
authors.forename: Anna-Carin
authors.initials: AC
authors.lastname: Lundell
authors.affiliation: Department of Rheumatology and Inflammation Research, Institute of Medicine, The Sahlgrenska Academy, University of Gothenburg , Gothenburg, Sweden.
authors.forename: Inger
authors.initials: I
authors.lastname: Nordström
authors.affiliation: Department of Rheumatology and Inflammation Research, Institute of Medicine, The Sahlgrenska Academy, University of Gothenburg , Gothenburg, Sweden.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Andersson
authors.affiliation: Department of Clinical Bacteriology, Institute of Biomedicine, The Sahlgrenska Academy, University of Gothenburg , Gothenburg, Sweden.
authors.forename: Ingegerd
authors.initials: I
authors.lastname: Adlerberth
authors.affiliation: Department of Clinical Bacteriology, Institute of Biomedicine, The Sahlgrenska Academy, University of Gothenburg , Gothenburg, Sweden.
authors.forename: Agnes E
authors.initials: AE
authors.lastname: Wold
authors.affiliation: Department of Rheumatology and Inflammation Research, Institute of Medicine, The Sahlgrenska Academy, University of Gothenburg , Gothenburg, Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Rudin