Figure 4

Protection against diarrhea and prevention of viral shedding achieved by oral administration of monovalent larva-derived VHHs 2KD1 or 3B2 in suckling mice challenged with RV. Pups were fed 100 μg (100 μl) of each larva-derived VHH intragastrically from days 0 to 5 once a day. At day 1, the pups were challenged intragastrically with RV 2 h after routine feeding. A. Percentage of pups protected from diarrhea with 300 DD50 of murine RV ECw at a range of post-infection days. B. Viral shedding was quantified by ELISA in the 10% (wt/vol) small intestine homogenates. The Fisher exact test was used to compare the proportions of pups with diarrhea and viral secretion among the groups. Antibody 2KA4 (divalent VHH antibody) or VP6 protein, both also produced in larvae, were used as controls.