Creating vaccine from a healthy host is a common practice. With that principle, anti bacteria Aeromonas hydrophia for fish is produced. It is a new way of using chicken as host, producing egg yolk containing Immunoglobulin Y.
The immunoglobulin Y is mixed with fish pellet and fed to the fish. The fish will develop immunity to the bacteria and a 14-days test showed good result, reducing the-death rate to 0%. A 30-days test showed even better result.