Safety and immunogenicity of inactivated Rift Valley Fever Smithburn viral vaccine in sheep

Virology Journal

Research

Thandeka Khoza¹  Nobalanda Mokoena²  Leeann Naicker²  Matome Selina Matsiela³ 

[1] Department of Biochemistry, School of Life Sciences, University of KwaZulu-Natal (Pietermaritzburg Campus), 3209, Scottsville, KwaZulu-Natal, South Africa;Onderstepoort Biological Products (Pty. Ltd), 100 Old Soutpan Road, 0110, Onderstepoort, Pretoria, South Africa;Onderstepoort Biological Products (Pty. Ltd), 100 Old Soutpan Road, 0110, Onderstepoort, Pretoria, South Africa;Department of Biochemistry, School of Life Sciences, University of KwaZulu-Natal (Pietermaritzburg Campus), 3209, Scottsville, KwaZulu-Natal, South Africa;

关键词: Rift valley fever virus;    Smithburn vaccine;    Virus inactivation;    Montanide™ Gel-01 adjuvant;    Aluminium hydroxide adjuvant;   

DOI  :  10.1186/s12985-023-02180-2

 received in 2023-06-15, accepted in 2023-09-07,  发布年份 2023

来源: Springer

【 摘 要 】

BackgroundThe live-attenuated Rift Valley Fever Smithburn (SB) vaccine is one of the oldest products widely used in ruminants for control of RVF infections. Vaccinations with RVF Smithburn result in residual pathogenic effect and is limited for use in non-pregnant animals. Commercially available RVFV inactivated vaccines are considered safer options to control the disease. These products are prepared from virulent RVFV isolates and present occupational safety concerns. This research study evaluates the ability of an inactivated SB vaccine strain to elicit neutralising antibody response in sheep.MethodsThe RVF Smithburn vaccine was inactivated with binary ethylenimine at 37 °C. Inactivated RVFV cultures were adjuvanted with Montande™ Gel-01 and aluminium hydroxide (Al (OH)3) gel for immunogenicity and safety determination in sheep. The commercial RVF inactivated vaccine and a placebo were included as positive and negative control groups, respectively.ResultsInactivated RVFV vaccine formulations were safe with all animals showing no clinical signs of RVFV infection and temperature reactions following prime-boost injections. The aluminium hydroxide formulated vaccine induced an immune response as early as 14 days post primary vaccination with neutralising antibody titre of 1:20 and a peak antibody titre of 1:83 was reached on day 56. A similar trend was observed in the animal group vaccinated with the commercial inactivated RVF vaccine obtaining the highest antibody titre of 1:128 on day 56. The neutralizing antibody levels remained within a threshold for the duration of the study. Merino sheep vaccinated with Montanide™ Gel-01-Smithburn were characterised with overall lower immune response when compared to aluminium hydroxide vaccine emulsions.ConclusionsThese finding suggests that the inactivated RVF Smithburn vaccine strain adjuvanted with aluminium-hydroxide can be used an alternative to the products prepared from virulent RVFV isolates for protection of ruminants against the disease. The vaccine can further be evaluated for safety in pregnant ewes.

【 授权许可】

CC BY   
© BioMed Central Ltd., part of Springer Nature 2023

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