Antibody responses in pigs vaccinated with the recombinant adenoviruses. (A) IgG specific to GP5 were detected in serum samples of pigs (n = 14 per group) at various time points by indirect ELISA. Bronchoalveolar lavage fluid (BALF) of pigs were collected at 49 days post primary immunization and IgG (B) or IgAs (C) specific to GP5 were determined by indirect ELISA (n = 8 per group). Data are expressed as the mean + SEM. When two sets of data are labeled with superscripts of different letters, it indicates that these sets of data are statistically different (P < 0.01) for (A) or (P < 0.05) for (B) and (C).