Antigenic relationships of selected strains of infectious pancreatic necrosis virus and European eel virus

Abstract

Abstract. An antigenic comparison of ten strains of infectious pancreatic necrosis virus (IPNV) and a single strain of European eel virus (EEV) revealed the presence of three distinct groups separable by cross‐neutralization. The 1/ r value calculated from the formula r=√r 1 × r 2 (Archetti & Horsfall 1950) was used to divide the virus strains into: group I, which included all six U.S.A. strains: Buhl, Idaho; Reno, Nevada; ATCC VR 299; Powder Mill, New Hampshire; West Buxton, Maine; and Cascade Locks, Oregon: group II, the European strains: ?Honnincthun, France; Sp Denmark; and Bonnamy, France: group III, Ab Denmark and EEV. The group II European strains of IPNV were more closely related to the group I U.S.A. strains than to those viruses in group III. European eel virus (EEV) was antigenically most closely related to the Ab strain of IPNV.