Pilot studies (Phase I, 1986 SBIR solicitation) showed that the infectious hematopoietic necrosis virus (IHNV) was reversibly adsorbed onto affinity media. This important first step of concentrating waterborne viral antigen allowed vaccines to be made and tested. Some conferred good protection against disease challenge. Only short-term protection was tested - results are encouraging and should translate into detailed specifications for affinity adsorbents used to make cost-effective vaccines against viral diseases such as IHNV in salmonids. This project will attempt to develop a vaccine for the IHNV disease of salmon. The research will examine bonding properties (core polymers to co-sorbents to virus) and antigen adsorption/desorption under controlled ionic strength, pH, solute quality, etc. This information will be used to optimize antigen concentration, treatment, and transfer to trout. Acceptable affinity media will be reasonably specific, have bond energies of the right order, and be economical. In addition, responses to antigen challenges to include large populations in natural epizootics and compare them with other virus models. Infectivity is to be screened and titered by standard cell culture methods, antigen...quantified by enzyme-linked immunosorbent assays, and protection...estimated by vaccinated animals better survival over controls after pathogen challenge. Correlations among these results will dictate further development and commercialization of a vaccine for IHNV disease of trout. The vaccine's composition, form, and prescribed delivery must permit trout to take up antigen and stimulate protection against natural infection over sufficiently a long term. And it must be practical.
