Seasonal variation in BCG-induced trained immunity

• DOI: 10.1016/j.vaccine.2024.07.010
• Publication Date: 2024-07-08T20:05:10Z
• Authors: Gizem Kilic; Priya A. Debisarun; Ahmed Alaswad; Marijke P. Baltissen; Lieke A. Lamers; L. Charlotte J. d...; Christine S. Benn; Peter Aaby; Helga Dijkstra; Heidi Lemmers; Joost H.A. Martens; Jorge Domínguez-A...; Reinout van Crevel; Yang Li; Cheng-Jian Xu; Mihai G. Netea
• Keywords: Heterologous; BCG vaccine

The Bacille Calmette-Guerin (BCG) vaccine is a well-established inducer of innate immune memory (also termed trained immunity), causing increased cytokine production upon heterologous secondary stimulation. Innate responses are known to be influenced by season, but whether seasons impact induction immunity not known. To explore the influence season on induced BCG vaccine, we vaccinated healthy volunteers with either during winter or spring. Three months later, measured ex vivo against stimuli, analyzed gene expressions and epigenetic signatures cells, compared these baseline before vaccination. vaccination stronger increase in pro-inflammatory cytokines peripheral blood mononuclear cells (PBMCs) stimulation different bacterial fungal In contrast, resulted lower IFNγ release PBMCs spring Furthermore, NK winter-vaccinated people had greater capacity only minor effects transcriptome monocytes 3 later. identified season-dependent changes vaccination, partly explaining higher cell reactivity group. These results suggest that more prone induce robust response activating reprogramming especially cells. (Dutch clinical trial registry no. NL58219.091.16)