FIG. 4.

SARS-CoV pseudovirus-neutralizing activity. Purified IgG from sera (A) and IgA from either intestinal or bronchoalveolar lavage fluids (B) were evaluated for SARS pseudovirus-neutralizing activities. Mice immunized either orally or intranasally were sampled at the indicated number of weeks after the first immunization. Approximately 100 infectious units of pseudovirus were used. Con., control; P.C., positive control. The assays were performed in duplicate, and the graphs are representative of two independent experiments. The error bars represent standard deviations.