Epitope profile of the first U.S. outbreak isolate RHDV IA-00. The RHDV IA-00 isolate was subtyped by antigen capture ELISA using a panel of monoclonal antibodies. Previous studies and communication from Lorenzo Capucci  have determined that monoclonal antibodies 1H8, 2A10, and 1H3 recognize the original serotype of RHDV while antibodies 3D4, 3B12, 2E1, 3D6, and 5D11 recognize RHDVa-specific epitopes. Additional monoclonal antibodies used (6H6, 1F10, 3H6, 6F9, 2B4, and 2G3) were not subtype-specific. The IA-00 isolate (black bars) correlated in antibody recognition profile to a prototype RHDVa strain, Pavia 1997 (grey bars). The Brescia 1989 strain (stippled bars) was used as an original RHDV serotype virus control. Normal liver from an uninfected rabbit served as a negative control (white bars).