Fig. 4

Induction of predominantly Th1-biased T cell responses by SW0123. C57BL/6 mice received either an one-dose (OD) vaccination with 3 or 30 μg SW0123 in week 0 or two-dose (TD) vaccinations with the same dosage in weeks 0 and 3. BALB/c mice were immunized twice with 3 or 30 μg SW0123 in weeks 0 and 3. Mice in the mock group were administrated with empty vector as control. (n = 5 in week 5; n = 4 in week 13). a, d Splenocytes were isolated 5 and 13 weeks after the first vaccination. Following stimulation with S protein overlapping peptides for 20 h, IFN-γ-producing T cells were quantified with an ELISpot assay. b, c, e, f Splenocytes isolated 13 weeks after first vaccination were stimulated with S protein overlapping peptides for 6 h, and Spike specific cytokine-producing CD4⁺ and CD8⁺ T cells were measured with an intracellular cytokine recall assay. Two-tailed Mann–Whitney test was used for statistical analysis. *p ≤ 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001