The CD4+ T cell response to structural peptides had stable responses post-infection (Fig. 5a) (r = 0.1475, p = 0.2265, Spearman two-tailed correlation), whilst structural-specific CD8+ T cell responses had a moderate significant trend for increased responses with time (Fig. 5B) (r = 0.4194, p = 0.0003, Spearman two-tailed correlation). This evidence concerns the gene CD4 and infection.