Fish vaccines.

Fish vaccines can be delivered the same way we immunize warm-blooded animals. Fish can be immunized by immersion in vaccine for a short period of time--30 seconds to 2 minutes. They can be immunized by injection, intramuscularly or intraperitoneally, and orally by mixing vaccines with feed either by top dressing or by incorporating into feed as an ingredient. Fish also respond to vaccine the same way as other animals do, but since fish are cold-blooded animals, the response to vaccine depends largely on the water temperature. In general, the higher the water temperature, the faster the immune response of fish to the vaccine. During the past 20 years fish vaccines have become an established, proven, and cost-effective method of controlling certain infectious diseases in aquaculture worldwide. Fish vaccines can significantly reduce specific disease-related losses resulting in a reduction of antibiotics use. The final result is the decrease of overall unit costs and more predictable production. Fish vaccines are advantageous over antibiotics because they are natural biological materials that leave no residue in the product or environment, and therefore will not induce a resistant strain of the disease organism. Fish vaccines are licensed by the federal government and closely regulated in the same manner as all other veterinary vaccines to ensure safety, potency, and efficacy. Even though commercial vaccines for aquaculture work really well in terms of protecting the fish against certain diseases, they should be used only as part of the overall fish health management program, because fish vaccines are not a cure-all. Animal husbandry is still the key to success in aquaculture.