WASHINGTON, D.C. — Dalan Animal Health announced early test results for a potential shrimp vaccine at the World Vaccine Congress in Washington, D.C. The potential vaccine administers inactivated bacteria to adult brood stock, which results in offspring born with inherited immunity.
Laboratory trials indicated the shrimp vaccine increased survival rates from 27 percent to 48 percent when exposed to Vibrio parahaemolyticus bacteria. In additional laboratory trials, the vaccine increased survival rates from zero percent to 58 percent when exposed to white spot syndrome virus.
Dalan Animal Health is planning field trials in Southeast Asia, beginning in Indonesia. These trials aim to gather efficacy data and seek regulatory approval. Crustacean infectious disease researcher Arun Dhar said, "Field data would really indicate the true efficacy."
Invertebrates, including shrimp, possess an innate immune system but do not have an adaptive immune system. Erin Strait, a veterinarian and chief scientific officer, said, "For a long time, it was considered that it was impossible, like vaccination couldn't happen. That, in recent years, has been proven to not be true."
Scientists believe innate immune memory is achieved through epigenetic modifications to DNA. These modifications do not alter the genetic sequence and can be passed to subsequent generations. Both the honeybee and shrimp vaccines provide protection against multiple pathogens, including those different from the source used in the vaccine formulations.
The U.S. Department of Agriculture granted conditional approval to the first vaccine for honeybees three years ago. This honeybee vaccine is formulated using inactivated Paenibacillus larvae bacteria, which cause American foulbrood disease. Feeding the honeybee vaccine to a queen increases her offspring's resistance to the targeted bacteria and a virus transmitted by varroa mites. The honeybee vaccine is currently distributed across farms in the U.S. and Canada. The beekeeping industry is valued at more than $10 billion, and disease and pest losses cost the industry an estimated hundreds of millions of dollars annually. The shrimp aquaculture industry is valued at tens of billions of dollars.