The Ad5-nCoV vaccine induces a durable cellular immune response.
The cellular immune response (IFN-γ-positive cells from isolated PBMCs) was evaluated following the SARS-CoV-2 vaccine using an enzyme-linked immunospot (ELISpot) assay. Peripheral blood mononuclear cells were isolated from blood samples taken from each participant in the Placebo (n = 19) and Ad5-nCoV (n = 50) groups. Participants were a subset from the FAS for immunogenicity analysis population. Isolated PBMCs were seeded at 3 x10Compared with the response observed in the Placebo group, those in the Ad5-nCoV group displayed significantly higher numbers of IFN-γ-positive T cells, regardless of how the cells were stimulated, on Days 14 (p<0.001) and 28 (p<0.01). However, 6 months post-vaccination, the differences between the groups were not statistically significant when cells were stimulated with the recombinant S protein ectodomain (p = 0.6) or with the peptide pool (p = 1.0).As shown in 