Effect of oral booster vaccination of rainbow trout against Yersinia ruckeri depends on type of primary immunization. Issue 85 (February 2019)

• Record Type: Journal Article
• Authors: Jaafar, Rzgar M.; Al-Jubury, Azmi; Dalsgaard, Inger; MohammadKarami, Asma; Kania, Per W.; Buchmann, Kurt
• Is Part Of: Fish & shellfish immunology. Issue 85(2019)
• Page Start: 61
• Page End: 65
• Publication Date: 2019-02
• Subjects: Vaccination -- Oral -- Dip -- Bath -- Yersinia ruckeri -- IgM; Fishes -- Immunology -- Periodicals; Shellfish -- Immunology -- Periodicals; Poissons -- Immunologie -- Périodiques; Crustacés -- Immunologie -- Périodiques; 571.9617
• DOI: 10.1016/j.fsi.2017.10.049
• Languages: English
• ISSNs: 1050-4648

Abstract

Abstract: Vaccination of rainbow trout against Enteric Redmouth Disease (ERM) caused by Yersinia ruckeri can be successfully performed by administering vaccine (a bacterin consisting of formalin killed bacteria) by immersion, bath or injection. Booster immunization is known to increase the protection of fish already primed by one of these vaccination methods. Oral vaccination of trout (administering vaccine in feed) is an even more convenient way of presenting antigen to the fish but the effect of an oral booster has not previously been described in detail. The present work describes to what extent protection may be enhanced by oral boostering following priming with different administration methods. The study confirms that vaccination by 30 s dip into a bacterin (diluted 1:10) may confer a significant protection compared to non-vaccinated fish. The immunity may be optimized by booster immunization either provided as dip (most effective), bath (less effective) or orally (least effective). Oral immunization may be used as booster after dip but applied as a single oral application it induced merely a slight and statistically non-significant response. It is noteworthy that primary oral immunization followed by an oral booster vaccination showed a trend for an even weaker response. It should be investigated if continued exposure to a low antigen concentration – as performed by two oral immunizations - may induce tolerance to the pathogen and thereby leave the fish more vulnerable. Highlights: Vaccine induced protection can be optimized by booster dip (most effective), bath (less effective) or oral (least effective). Oral immunization may be used as booster after dip vaccination. Oral primary vaccination followed by an oral booster conferred no protection.