Evaluation of Duration of Immunogenicity and Protective Efficacy of Improved Influenza Viral Vector–Based Brucella abortus Vaccine Against Brucella melitensis Infection in Sheep and Goats

Frontiers in Veterinary Science

Kaissar Tabynov¹  En-Min Zhou²  Gourapura J. Renukaradhya³  Aigerim Mailybayeva⁵  Sholpan Ryskeldinova⁵  Nadezhda Zinina⁶ 

[1] Biological Safety Department, Kazakh National Agrarian University, Almaty, Kazakhstan;;Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, China;Food Animal Health Research Program, Department of Veterinary Preventive Medicine, College of Food Agricultural and Environmental Sciences, The Ohio State University, Wooster, OH, United States;Laboratory of Infectious Disease Prevention, Research Institute for Biological Safety Problems, Gvardeiskiy, Kazakhstan;Laboratory of Microbiology, Research Institute for Biological Safety Problems, Gvardeiskiy, Kazakhstan;

关键词: Brucella melitensis;    influenza viral vector;    vaccine;    T-cell–mediated immune response;    prolonged efficacy;    small ruminants;   

DOI  :  10.3389/fvets.2020.00058

来源: DOAJ

【 摘 要 】

In this study, we first evaluated the duration of a protective immune response against Brucella melitensis infection in non-pregnant sheep and goats immunized with an improved (by vaccine formulation and route of administration) commercial Brucella abortus vaccine based on influenza viral vectors expressing Brucella immunodominant Omp16, L7/L12, Omp19, or Cu-Zn superoxide dismutase (SOD) proteins (Flu-BA_Omp19-SOD). Sheep and goats in the vaccinated group were immunized thrice concurrently via the subcutaneous and conjunctival routes of administration at an interval of 21 days. Animals in the control group were administered with 20% Montanide Gel01 adjuvant in phosphate-buffered saline in the same way. We showed that the Flu-BA_Omp19-SOD vaccine in sheep and goats induces antigen-specific Th1-biased [immunoglobulin G2a (IgG2a) over IgG1] antibody response and T-cell and interferon γ responses lasting over a period of 1 month post–last vaccination (PLV). The levels of protection against B. melitensis 16M infection (vaccination efficacy) in vaccinated sheep for a period of 6 months were 0–20% and in goats 20–40% compared to control challenge group. But the severity of B. melitensis 16M infection in the Flu-BA_Omp19-SOD–vaccinated sheep and goats during the entire period of observation revealed the infection index (P = 0.001–P < 0.0001) and Brucella colonization in lymph nodes and organs (P = 0.04–P < 0.0001) were significantly lower than those in the control group. To conclude, the Flu-BA_Omp19-SOD vaccine using improved formulation and administration method in sheep and goats provides augmented antigen specific humoral and T-cell immune response lasting only for 1 month PLV and partial protection for 6 months against B. melitensis 16M infection.

【 授权许可】

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