Fish Immunology (1+1)

Unit 14 - Vaccine

14.8. Immersion vaccination
Fish being aquatic in nature it is constantly surrounded by the microorganisms of which some may be pathogenic ones. These fish have a mechanism to recognize these pathogens and elicit an immune response. So when the fish comes in contact with vaccine during immersion these vaccine is absorbed by the skin and gills, the specialized cells such as antibody-secreting cells are activated and will protect the fish during the later stage of exposure to the pathogen.
Immersion vaccine can be applied in two ways:-

• Dip method
• Bath method

Dip method
In dip vaccination method fish are immersed in a highly concentrated vaccine solution for very short time say usually few minutes.
Bath method
In bath vaccination method fish are immersed in a lower concentration of vaccine solution for a longer period, usually one to several hours.
Advantages
• Suitable for mass vaccination of all sizes of fish
• Reduced stress for fish
• Lower labour costs
• Less risk to vaccination team
Disadvantages
• Major disadvantages are the large amount of vaccine required
• Lower level of protection and
• Low duration of immunity