Mucosal immune responses to DEV measured by ELISA. (A) Bile IgA responses to DEV. (B) Duodenum IgA responses to DEV. Bile and duodenum were obtained at different time points and assayed by end-point dilution ELISA using DEV as a coating antigen. Numbers on the y-axis represent the means of average OD450 ± standard deviations (n = 3). Statistical significance was determined using a student’s t-test.