Multivalent Oral Vaccine Development against Lactococcosis Disease in Rainbow Trout Using Diatom-Based Technology

Infectious diseases have emerged and spread quickly due to intensive aquaculture which has hindered the sustainable expansion of the aquaculture sector. One significant concern is lactococcosis a threat posed by Lactococcus petauri L. garvieae and L. formosensis which endangers both cultivated and wild fish populations including trout. The disease has emerged in cultured trout in North America and has caused disease outbreaks with mortalities >90% in some populations in several states in the USA. However no licensed vaccine against piscine lactococcosis is currently available in the USA. Hence our project aims to provide an innovative solution to these challenges by mitigating and preventing early infections thus safeguarding the aquaculture industry from economic losses by developing oral aquaculture vaccines. Given the urgent need for vaccines against lactococcosis in the context of trout farming in the United States the SBIR Phase II project aims to develop and commercialize a diatom-based oral vaccine targeting L. petauri the primary etiologic agent of piscine lactococcosis in the USA. This effort utilizes the technology and accomplished outcomes from the SBIR Phase I grant focused on developing a vaccine against the fish pathogen Francisella orientalis. Our technology integrates microalgae into aquaculture feed creating a cost-effective multivalent oral aquaculture vaccine. Successful development of diatom-based vaccines could lead to the rapid generation of novel cost-effective fish vaccines against endemic emerging and re-emerging pathogens boosting the overall health and productivity of the U.S. aquaculture sector.