Serologic cross-reaction between bovine herpesviruses 1 and 4 by the enzyme-linked immunosorbent assay

Reciprocal cross-titrations using constant concentrations of bovine antiserum (1: 100) to either bovine herpesvirus (BHV) 1 or BHV 4 (obtained from controlled infection status) against varying concentrations of both viral antigens in enzyme-linked immunosorbent assay (ELISA) indicated a subtle difference between the antigenic composition of these 2 agents. Although control antiserum consistently yielded higher ELISA titers against homologous viral antigen, a considerable cross-reactivity between the 2 viruses was observed. Based on control sera results, serologic profiling of field bovine serum samples against both BHVs 1 and 4 antigen preparations indicated that the ELISA was unsatisfactory for distinguishing between previous BHV 1 or 4 exposure. The ELISA, however, was more sensitive than the virus neutralization test for detecting antibodies to BHVs 1 and 4 in cattle sera.