FIG. 1.

Construction and immunogenicity of rAd35 vaccine vectors expressing vaccinia virus antigens. Four rAd35 vectors expressing vaccinia virus A27L, A33R, B5R, and L1R under the control of a cytomegalovirus promoter and polyadenylation signal were produced. A27L and L1R represent IMV antigens; A33R and B5R represent EEV antigens. BALB/c mice (n = 4/group) were injected once i.m. with 10¹⁰ vp of rAd35-Empty (sham vaccine), rAd35-A27L, rAd35-A33R, rAd35-B5R, rAd35-L1R, or a mixture of the four rAd35 vaccine vectors (Mix; each at 2.5 × 10⁹ vp). At week 4 following immunization, antigen-specific antibody titers were assessed by ELISA (A), IMV-specific NAb titers were determined by luciferase-based virus neutralization assays (B), EEV-specific NAbs were assessed semiquantitatively by comet reduction assays (C), and antigen-specific cellular immune responses were assessed by pooled peptide IFN-γ ELISPOT assays (D). Positive controls included VIG and splenocytes and serum from vaccinia virus-infected mice (Vac).