Intestinal IgA response and immunity to rotavirus infection in normal and antibody-deficient chickens.

Rotavirus inoculation by oesophageal cannulation resulted in subclinical infection without decreasing intestinal D-xylose absorption in both intact and embryonally bursectomised, antibody-deficient (EBx) 8-week-old specific-pathogen-free chickens. In intact chickens, rotavirus-specific IgM, IgG and IgA responses were detected in serum, while the intestinal antibody response consisted almost entirely of IgA Serum IgG and intestinal IgA levels were increased for at least 70 days following a single inoculation with the virus. Intact chickens recovered from a primary rotavirus infection between 4 and 14 days post inoculation (dpi) and developed resistance to homotypic challenge between 14 and 28 dpi. These responses were only slightly delayed in EBx birds, which recovered from primary infection between 8 and 28 dpi and developed resistance between 14 and 42 dpi. This suggested that the intestinal IgA response in chickens participated in both recovery from and resistance to rotavirus infection, but that it was not the only mediator of recovery and resistance.