Fig. 5: Transmission properties of SARS-CoV-2 in ferrets of different ages upon co-housing naïve ferrets.

Naïve ferrets (n = 3/group) were exposed to direct contact (DC) with each group of infected ferrets of different ages (n = 3/group) starting 24 h after the primary infection, followed by measurement of their viral titers from nasal washes on day 1, 3, 5, 7, 9, and 11 post contact (a). Serum neutralizing antibody titers in contact groups at 12 dpc (b). IgG titers in contact groups at 12 dpc (c). Data are presented as mean values ± SEM. Groups with the same letter are of the same subgroup in the post-hoc analysis. Lower case letters indicate significant differences at each time point (P values are a vs b: 0.00897, a vs c: 0.00046, b vs c: 0.03398, d vs e: 0.0013 or 0.0019, f vs g: 0.00175 or 0.00024, h vs i: 0.0036 or 0.0171, j vs k: 0.00088 or 0.00015, l vs m: <0.0001 and n vs o- 0.00058 or 0.00013 (a), a vs b: 0.0009 or <0.0001 (b), a vs b: 0.0031, a vs c: <0.0001 and b vs c: 0.0053 (c)), while upper case letters indicate significant differences of area under the curve as change over the entire period (P values are A vs B: 0.00844, A vs C: < 0.0001, B vs C: 0.00014 and D vs E: 0.0001 or <0.0001 (a), A vs B: 0.0009 or <0.0001 (b), A vs B: 0.0031, A vs C: < 0.0001 and B vs C: 0.0053 (c)). The area under the curve was calculated using Kruskal–Wallis with Bonferroni as a post-hoc analysis. Data were analyzed in GraphPad Prism 9.1.2. Source data are provided as a Source Data file.