Fig. 2

Determination of T-cell immune responses and effective vaccine dose. A After 130 days post-immunization with the ssAAV5-RBD-plus vaccine, populations of memory CD4⁺ T and CD8⁺ cells B were significantly increased; C Secretion of IFN-γ from CD8⁺ cells was significantly upregulated; Among doses of 1×10¹¹, 1×10¹⁰1, 1×10⁹, 1×10⁸ GCs, the amount of IgG (D) and NAs (E) indicates that 1×10¹¹ GCs had the most robust immunogenicity; Among doses of 1×10¹¹, 2×10¹¹ and 4×10¹¹ GCs, the amount of IgG (F) and NAs (G) 1×10¹¹ GCs had the most robust immunogenicity. Values represent mean ± SEM; significant difference versus control group, **P < 0.01.