Fig. 3

Anti-EHV-1 gC antibodies in nasal secretions after infection with EHV-1 strain Ab4 or its deletion mutant Ab4ΔORF2. Three groups of horses (n = 8/group) were either not infected (control), infected with the neuropathogenic EHV-1 strain Ab4 (Ab4) or infected with its ORF2 deletion mutant (Ab4ΔORF2) on day 0 (arrow). Before (day − 1) and after (day 1–260) experimental infection EHV-1 gC specific total Ig (a), IgG1 (b), IgG4/7 (c), IgA (d), IgG1/3 (e), and IgG3/5 (f) were quantified in nasopharyngeal secretions by fluorescent bead-based multiplex assays and expressed as median fluorescent intensities (MFI). Note that Y-axes scales differ depending on isotype. Mean and standard errors are plotted for each group. Significant differences between groups are marked: a = Ab4 vs. control, b = Ab4ΔORF2 vs. control, c = Ab4 vs. Ab4ΔORF2