Vaccination and resistance breeding constitute two out of the classical four control strategies for control of infectious diseases in animal production.   In European freshwater aquaculture however, their inherent potential is still under-exploited, leaving chemotherapy and zoo-sanitary measures as the dominant and often insufficient means of disease control.  There is a strong need for  development of new and effective vaccines for salmonid infections like rainbow trout fry syndrome (RTFS) and streptococcosis/lactococcosis, and for the sophistication of industrial vaccination programmes.  For salmonid diseases like yersiniosis and furunculosis, there is a need for demonstration projects to overcome costly licensing hurdles currently limiting the availability of these products in many national and regional market segments.  Innovative immunisation technologies that provide excellent protection against rhabdovirus infections (VHS and IHN) have recently been developed but support to guide these methods through  the regulatory progress is needed.  In the field of disease resistance breeding against VHS,  results are promising but studies covering further important diseases, and demonstration projects showing the industrial feasibility of selection for disease resistance are needed.   The implementation of several disease control strategies in parallel, and  improving producer implementation of vaccination and resistance breeding strategies is being advocated.

Dr. Paul J. Midtlyng is educated a veterinarian and has worked with fish diseases since 1983, focussing mainly on a disease prevention and control. He did his Ph.D on experimental and field vaccination trials in salmon. Paul J. Midtlyng is head of research and development at VESO, and has recently organised a large international symposium of Fish Vaccinology  (Bergen, April 9-11, 2003).

Contact details:  Head, Research & Development, VESO, PO Box 8109 Dep., NO-0032 Oslo, Norway. Tel: +47 2296 1120, Fax: +47 2296 1101. E-mail: paul.midtlyng@veso.no.