Fig. 9. LNP-based DNA vaccine-induced potent immune response against SARS-CoV-2 infection and its variants in hamsters.

A Scheme of immunization. Syrian hamsters were immunized with controls and LNP-HPS, and boosted with equivalent doses 3 weeks later. Immunized mice were challenged with 6 × 10⁵ PFU of SARS-CoV-2 variants Gamma lineage (P.1), sera was collected at 24 h before the infection and 5 days post infection for all immunized groups. Levels of total antigen-specific IgG anti-spike serum of hamsters B at pre-infection, and C 5 days post infection (n = 4/group). Levels of neutralizing antibodies in sera of immunized hamsters at D, E pre-infection, and F, G 5 days post infection against P.1 (n = 5/group). Levels of neutralizing antibodies in sera of immunized hamsters at H, I pre-infection, and J, K 5 days post infection against Omicron (n = 5/group). Data are presented as mean ± SEM; ns not significant, *p < 0.05. E, I, G, K Kruskal–Wallis followed by Dunn’s multiple comparisons test. Source data are provided as a Source Data file.