Global blood miRNA profiling unravels early signatures of immunogenicity of Ebola vaccine rVSVΔG-ZEBOV-GP

We characterized the intracellular miRNAs, isolated from whole blood cells (WB), induced by vaccination against Ebola. We identified early miRNA signatures associated with the ZEBOV-specific IgG antibody responses at day 28 or 360 post-vaccination. We isolated total RNA including miRNA from whole blood from 48 healthy individuals receiving the rVSVΔG-ZEBOV-GP vaccine or placebo. Timepoints day 0 (baseline before vaccination), and days 1, 2, 3, and 7 post-vaccination have been considered. We performed miRNA-seq. We then identified differentially expressed miRNAs by comparing rVSVΔG-ZEBOV-GP vaccines vs placebo controls. Next, we correlated baseline and early miRNAs with the ZEBOV-specific IgG antibody titer measured at day 28 and day 360 by performing Pearson Correlation. We used Machine Learning algorithms to identify the best early miRNA signatures able to discriminate high and low antibody levels at day 28 and day 360. Finally, we identified a miRNA antibody predictive signature associated with immune-related target mRNAs and corresponding pathways.