An Oral Vaccination Method with the Aid of Capsaicin against Viral Nervous Necrosis (VNN)

Abstract

Fish farming has always involved a risk of microbial infections, especially those caused by pathogenic viruses, for which chemotherapeutics are generally ineffective. Viral nervous necrosis (VNN), otherwise known as viral encephalopathy and retinopathy (VER), caused

Betanodavirus and VER Disease: A 30-year Research Review

“…injection [289,328,329,331,332,349]. Injection has also been used for DNA vaccines [347,349] and subunit vaccines [335,336,338,[340][341][342] and oral immunization strategies have been used either for inactivated, subunit or DNA vaccines [225,[333][334][335]341,343,348,351,352]. The oral vaccine was given to the fish mixed with food [343] or by oral gavage [333,341] and encapsulated using either chemical compounds [225,348] or Artemia [353].…”

“…The oral vaccine was given to the fish mixed with food [343] or by oral gavage [333,341] and encapsulated using either chemical compounds [225,348] or Artemia [353]. Furthermore, an oral inactivated vaccine has been demonstrated to confer protection in seven-band grouper after supplementation with capsaicin (a natural substance exerting an intestinal inflammatory reaction) [352].…”

Comparative immunohistological study on using capsaicin, piperine, and okadaic acid for the transepithelial passage of the inactivated viral and bacterial vaccines in fish

“…The candidate inflammatory substances were: capsaicin (Wako chemicals, Japan), piperine (Wako chemicals, Japan) and okadaic acid (Wako chemicals, Japan). The present used doses was decided depending upon the non-destructive degree of intestinal inflammation observed in previous research (Berven, & Seglen, 2001;Gaafar et al, 2015;Gaafar et al, 2018;Khajuria, & Zutshi, 2002).…”

“…Furthermore, enhancing antigen uptake by opening gaps between enterocytes by zonulaoccludens toxin (ZOT), which is an enterotoxin expressed by Vibrio cholerae that reversibly opens the intercellular tight junctions (TJs), (Fasano et al, 1991). Following similar concept of ZOT, the more safer and cheaper, capsaicin (methyl vanillylnonenamide) which is naturally produced from hot chili pepper (Surh & Lee, 1996) successfully aided the intestinal passage of NNV vaccine particles (Gaafar et al, 2015;Gaafar et al, 2018).…”

“…In previous studies, the authors observed that capsaicin; in addition to its proven intestinal inflammatory action; was effective at enhancing the trans-epithelial passage of the inactivated redspotted nervous necrosis virus (RGNNV) particles through goldfish Crassiusaurata (Gaafar et al, 2015). Furthermore, by applying the same method, a pilot in vivo post-oral vaccination challenge experiment with the same virus in sevenband grouper, gave rise to 100% survivability in vaccinated group (Gaafar et al, 2018). In this study, our aim is to find comparable materials to capsaicin that can exert the same; or even similar effects; to assess their suitability as oral vaccine adjuvant candidates.…”