Serum and vaginal wash antibodies in Syrian hamsters following single intranasal immunization. Serum and vaginal wash samples were collected at 3, 6, 12, and 24 weeks post-single immunization. Serum anti-GFP (A) and anti-Ad6 (B) and vaginal wash anti-GFP (C) and anti-Ad6 (D) antibodies were measured by ELISA. Data were analyzed by two-way ANOVA with Bonferroni multiple-comparison posttest. *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001.