a) Volcano plot highlighting differentially expressed genes (DEGs, false-discovery rate [FDR] <0.01; red upregulated and blue downregulated) at each study time point versus pre-vaccination (4 months of age) 4 hours post-vaccination (719 DEGs, n=28). P-values were obtained from the moderated t-statistic, after adjustment for multiple testing (Benjamini and Hochberg's method). The top 10 genes, ranked by FDR, are labelled. 