Oral antiviral vaccines in aquaculture: Current status, challenges, and future prospects

Vaccination remains the most effective strategy for preventing viral infections in the aquaculture industry. Most commercially available antiviral vaccines are produced from attenuated viral particles and administered via intraperitoneal or intramuscular injection. While this approach has proven effective concerns on safety, and the negative impact of injection on the welfare of the farmed fish species cannot be overlooked. Therefore, research have been geared towards finding effective oral vaccine alternatives to eliminate the need for fish handling without incurring additional operational costs. However, the instability of antigenic peptides in the harsh digestive enzymatic conditions becomes a major setback to adequately stimulate optimum immune responses against viral pathogens. This article discusses progress, challenges, and future possibilities in the design and development of commercial and experimental oral vaccines for finfish and shellfish aquaculture species against viral infection.