Adenovirus type 4 and 7 vaccination or adenovirus type 4 respiratory infection elicits minimal cross-reactive antibody responses to nonhuman adenovirus vaccine vectors

Abstract

Antivector immunity may limit the immunogenicity of adenovirus vector vaccines. We tested sera from individuals immunized with adenovirus type 4 and 7 (Ad4 and Ad7, respectively) vaccine or naturally infected with Ad4 for their ability to neutralize a panel of E1-deleted human and chimpanzee adenoviruses (ChAd). Small statistically significant increases in titers to ChAd63, ChAd3, human Ad35, and human Ad5 were observed. Neutralizing antibodies elicited by Ad4 infection or immunization results in a small amount of adenovirus cross-reactivity.

Figures

FIG 1

Vaccination or infection with Ad4 is associated with a small increase in neutralizing activity against common and rare human and primate adenoviruses (white bars represent pre-Ad exposure and gray bars post-Ad exposure titers). (A) Geometric mean titers (GMTs) and 95% confidence intervals (CI) for all subjects. The Kruskal-Wallis test was used to assess statistical significance. (B) Pie charts depicting frequency of pre-Ad exposure and post-Ad exposure titers by titer range. The Chi-square test was used to test statistical significance. There was insufficient sample to test sera against all isolates. *, P < 0.05; **, P < 0.001; ***, P < 0.0001. ns, not significant.