Vaccination can be a useful tool, said Roar Gudding during his presentation at Aquaculture Europe 2013. One way in which fish can be successfully protected is through herd immunity.
This technique allows all the fish in a stock to be protected through vaccinating only a proportion of the stock.
In order for all fish to be protected, the amount vaccinated needs to be greater than the number not vaccinated.
Giving an example, Mr Gudding showed how in Norway the application of a vaccine for furunculosis has led to decreased mortality. Each year after application, the number of mortalities decreased and, by the third year, there were no mortalities reported.
In this way, vaccines can be used as a tool by authorities to prevent the spread or occurrence of disease in an area.
