Figure 5

SARS-CoV-2 titers in upper and lower airways of inactivated vaccine-immunized hamsters following SARS-CoV-2 challenge. (a–d) Oropharynx swabs were obtained daily following challenge on day 44, according to the experiment outlined in Fig. 4, until euthanasia on day 49. (a, c) Virus genome titers following challenge with the original-D614G (a) or BA.1 (c) virus. The OVA immunized non-challenged group is included in both graphs for comparison. Curves represent group medians and dots represent individual values, n = 4 for each group except for the BA.1 challenged OVA immunized group on day 46 with n = 3 due to low sample recovery. (b, d) Infectious titers following challenge with the original-D614G (b) or BA.1 (d) virus; I-P60 and I-P60/BA.1 symbols in (b) and (d) were nudged by +/− 0.04, respectively, on the y-axis. The OVA immunized non-challenged group is included in both graphs for comparison. (e) Virus genome titers in lung tissue obtained on day 49, n = 4 for each group, LLOQ is based on measurements from the OVA immunized non-challenged group (mean plus three times the standard deviation). < indicates that at least one value used to calculate the median is below LLOQ, colored according to group. Statistical analysis was only carried out between groups where all values were above the LLOQ. A Kruskal–Wallis test was used (significance indicated above the symbols) with a post-hoc Dunn’s multiple comparison test (line with brackets). A Mann–Whitney test was used when only two groups were above LLOQ (not significant). Only statistically significant differences are shown. *p < 0.05. OVA, ovalbumin. TCID₅₀, 50% tissue culture infectious dose. LLOQ, lower limit of quantification.