Fig 1: NiV∆F vaccination enhances Fc-mediated antibody effector functions.Groups of hamsters were vaccinated IN once 28 (blue), 14 (orange), 7 (green), or 3 (purple) days before challenge, or mock-vaccinated with DMEM (red) 28 days before challenge (total, n = 120; for each vaccination group, n = 24; 12 males and 12 females; all age matched). Animals were challenged either IN with 106 TCID50 (n = 60) or IP with 104 TCID50 (n = 60) with NiV strain Malaysia. At 1, 4, and 6 dpi, select animals were euthanized for analysis (n = 40 per dpi; n = 4 per vaccination period per vaccination route per day; two males and two females per group). (A and B) ADCD and (C and D) ADCP against N and G antigens. In all panels, individual animals are represented as circles, with a solid line indicating the mean at each time point. In all panels, significance is indicated in relation to mock-vaccinated animals (red dots) from the same time point after challenge, calculated by log two-way ANOVA with Dunnett’s test to correct for multiple comparisons: ****P ≤ 0.0001; ****P ≤ 0.001; **P ≤ 0.01; *P ≤ 0.05; ns, non significant. MFI, mean fluorescence intensity. (E) Single-cell suspensions of splenocytes collected 6 days after NiV challenge (IP or IN) from hamsters either mock-vaccinated (DMEM only) or VRP-vaccinated IN for indicated vaccine intervals before challenge were stained for fluorescence-activated cell sorting analysis. T cells were identified and stained for expression of CD3, CD4, and CD8, with levels depicted as % of viable cells. NK cells were identified and stained for expression of CD94 (gating strategy shown in fig. S4). Samples from NiV-infected hamsters were compared to those obtained from naïve (unvaccinated and uninfected) hamsters.