Abstract

Oral vaccination is the most desirable immunization method by which to prevent fish disease occurring at the early larval stage. We developed an Escherichia coli-based oral nervous necrosis virus (NNV) subunit vaccine and demonstrated its effectiveness in orange spotted grouper ( Epinephelus coioides) fry. However, the incubation period was determined to be over 2 weeks. To enhance the efficacy and shorten the incubation period, a safe and digestible biological adjuvant should be found. Vibrio anguillarum, a common marine bacterium with immune-stimulatory capability was selected as an expression host. An expression vector containing its heat shock protein 60 gene ( groE) as an inducible promoter was constructed to express recombinant NNV coat protein as an antigen. The recombinant V. anguillarum was inactivated and encapsulated in Artemia nauplii to formulate a V. anguillarum-based oral vaccine. Compared to the E. coli-based oral vaccine, this novel oral vaccine not only elicited a higher expression of Mx (encoding for an anti-viral protein) in the brain and viscera but also a higher specific antibody titer against NNV in the first week after inoculation. Meanwhile, a higher survival rate compared to an equal dosage of an E. coli-based oral vaccine was also noticed in two individual challenge trials, indicating that an antigen expressed in an V. anguillarum-based oral vaccine could enhance efficacy in a shorter incubation period and could reduce the risk of NNV infection.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.