Post-vaccine inflammation tracking: validation of a novel individualized digital inflammatory biomarker relative to serum biomarkers

Inflammatory changes play a central role in both diseases and therapeutic interventions. Wearables are a promising novel method for inflammation detection and tracking through identifying subtle, individualized physiologic changes. We evaluated a wearable-derived individualized digital biomarker, inflammatory multivariate change index (iMCI) against serum biomarkers and reactogenicity following vaccination. Sixty-one volunteers received one of four mRNA vaccines (80 total doses) and wore a torso sensor patch for 14 days starting seven days before vaccination. Changes in serum inflammatory biomarkers symptoms were tracked post-vaccine. iMCI showed moderate to strong correlation against C-reactive protein (CRP; Spearman ρ = 0.59, p < 0.01) and interferon-γ (IFN-γ; ρ = 0.56, p < 0.01), comparable to the CRP-IFN-γ correlation (ρ = 0.60, p < 0.01). Associations with systemic reactogenicity were moderate for all three measures (iMCI ρ = 0.48, p < 0.01; IFN-γ ρ = 0.34, p = 0.01; CRP ρ = 0.36, p < 0.01). These results indicate that a personalized digital biomarker offers a scalable alternative to serial blood testing for real-time inflammation tracking.