Fig. 3: Protective efficacy of NDV-PFS vaccination against SARS-CoV-2 variants of concern.

Syrian hamsters were vaccinated with NDV-PFS and challenged 28 days following their final dose with either Delta in (a–c) or Omicron (BA.2) in (d–f). a Weight loss in Delta-challenged hamsters. b Maximum weight loss in each of the individual hamsters challenged with Delta that were monitored throughout the course of the experiment. c TCID₅₀ titers in the tissues of each Delta-infected animal euthanized on day 5 post-infection. d Weight loss in BA.2 challenged hamsters. e Maximum weight loss in each of the individual hamsters challenged with BA.2 that were monitored throughout the course of the experiment. f TCID₅₀ titers in the tissues of each BA.2 infected animals were euthanized on day 5 post-infection. In b, c, e, and f, significance was assessed by the Kruskal–Wallis test with multiple comparisons. Exact p values are shown where significant differences are seen. n = 10 in a and d until day 5, and then n = 4. n = 4 in (b and e). n = 6 in (c and f). Shown are means + SEM in (a and d) and medians in (b, c, e, f).