Vaccines can have non-targeted or heterologous (also called non-specific) immunological effects on the immune system i.e. effects other than inducing an immune response against the disease targeted by the vaccine. This trial aims to evaluate the non-specific immunological effects of two vaccines - diphtheria-tetanus-acellular pertussis (DTP) vaccine and seasonal influenza vaccine - in a cohort of elderly humans (\>65 years of age) and healthy adult control subjects (30-50 years).
This prospective randomised study aims to investigate the heterologous immunological effects of DTP and seasonal influenza (Flu) vaccination in an elderly Tasmanian population and healthy adults. The study will assess whether prior or concurrent administration of DTP with seasonal Flu vaccination affects generalised inflammation / immune homeostasis and gene expression, with a particular focus of inflammation reactive cells. It will also analyse for effects of DTP on the induction of vaccine-specific immunity to seasonal influenza vaccination (antibodies and cellular). Volunteers will be randomised to one of three vaccine groups and serial blood samples taken for immunological assays for up to 30 weeks. The study is exploratory and will investigate vaccine effects on multiple immune parameters.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
NONE
Enrollment
450
Intramuscular standard seasonal influenza vaccine
Intramuscular DTaP vaccine
Clifford Craig Foundation
Launceston, Tasmania, Australia
RECRUITINGNumber of inflammation reactive TNFR2+ regulatory T cells per mL of blood
Change over time in different vaccine groups of Tregs measured by flow cytometry.
Time frame: 24 hours, 1 week, 4 weeks and 26 weeks
Whole human genome transcription profile by next generation sequencing in log2 expression levels
Differential gene expression 24 hours after vaccination compared to baseline, and vaccine groups compared to see which genes / pathways are affected. Differential transcription determined for each gene, then analysed using modular analysis tools to determine vaccine effects.
Time frame: 24 hours
Influenza-specific antibody titres to seasonal influenza vaccination
Change over time in the different vaccine groups of titres measured by haemagglutination inhibition assay.
Time frame: 4 weeks and 26 weeks
Pro-inflammatory (TNF) to anti-inflammatory (IL-10) cytokine ratio in stimulated blood in pg/mL
Change in TNF:IL-10 ratio post-vaccination over time as measured by cytokine multiplex assay of anti-CD3 stimulated PBMC.
Time frame: 24 hours, 1 week, 4 weeks and 26 weeks
Influenza-specific IFN-g CD4 T cell responses to seasonal influenza vaccination in pg/mL
Change over time in the different vaccine groups of IFN-g levels in supernatants from CD4 T cells cultured with live influenza virus
Time frame: 4 weeks and 26 weeks
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