Preliminary evaluation of a recombinant Rift Valley fever virus glycoprote in subunit vaccine providing full protection against heterologous virulent challenge in cattle

Authors: Wilson, William - Bill; FABURAY, BONTO - Animal And Plant Health Inspection Service (APHIS); TRUJILLO, JESSIE - Kansas State University; RAGAN, IZABELA - Colorado State University; SUNWOO, SUNYOUNG - Kansas State University; MOROZOV, IGOR - Kansas State University; SHIVANNA, VINAY - Kansas State University; BALOGH, AARON - University Of Wisconsin; URBIANIAK, KINGA - Kansas State University; MCVEY, D. SCOTT - University Of Nebraska; BOLD, DASHZEVEG - Kansas State University; GAUDREAULT, NATASHA - Kansas State University; SCHIRTZINGER, ERIN - Kansas State University; DAVIS, A. SALLY - Kansas State University; MA, WENJUN - Missouri State University; RICHT, JUERGEN - Kansas State University

Submitted to: Vaccines
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/16/2021
Publication Date: 7/6/2021
Citation: Wilson, W.C., Faburay, B., Trujillo, J., Ragan, I., Sunwoo, S., Morozov, I., Shivanna, V., Balogh, A., Urbianiak, K., McVey, D., Bold, D., Gaudreault, N., Schirtzinger, E.E., Davis, A., Ma, W., Richt, J.A. 2021. Preliminary evaluation of a recombinant Rift Valley fever virus glycoprote in subunit vaccine providing full protection against heterologous virulent challenge in cattle. Vaccines. 9(7):748. https://doi.org/10.3390/vaccines9070748.
DOI: https://doi.org/10.3390/vaccines9070748

Interpretive Summary: The mosquito-borne Rift Valley fever virus (RVFV) affects both animals and man and causes periodic outbreaks of abortion in ruminant species and hemorrhagic disease in humans in sub-Saharan Africa. These outbreaks have a significant impact on veterinary and public health. The introduction to the Arabian Peninsula in 2003 raised concerns of further spread of this transboundary disease to non-endemic areas. These concerns are supported by the presence of competent vectors in many non-endemic countries. There is no licensed RVF vaccine available for humans and only a conditionally licensed veterinary vaccine available in the United States. Current modified live attenuated virus vaccines employed in endemic countries lack the ability for differentiating infected from vaccinated animals (DIVA). Previously, the efficacy of our patented recombinant subunit vaccine was demonstrated in sheep. In the current study, vaccine formulations for were evaluated and the vaccine was demonstrated effective in cattle. This study supports the notion, that our subunit vaccine platform is able to prevent and control RVFV infections in target animals.

Technical Abstract: Rift Valley fever virus (RVFV) is a mosquito-borne zoonotic pathogen that causes periodic outbreaks of abortion in ruminant species and hemorrhagic disease in humans in sub-Saharan Africa. These outbreaks have a significant impact on veterinary and public health. The introduction to the Arabian Peninsula in 2003 raised concerns of further spread of this transboundary disease to non-endemic areas. These concerns are supported by the presence of competent vectors in many non-endemic countries. There is no licensed RVF vaccine available for humans and only a conditionally licensed veterinary vaccine available in the United States. Current modified live attenuated virus vaccines employed in endemic countries lack the ability for differentiating infected from vaccinated animals (DIVA). Previously, the efficacy of a recombinant subunit vaccine based on the RVFV Gn and Gc glycoproteins was demonstrated in sheep. In the current study, cattle were vaccinated subcutaneously with the Gn only, or Gn and Gc combined, with either one or two doses of the vaccine and then subjected to heterologous virus challenge with the virulent Kenya-128B-15 RVFV strain. The elicited immune responses by the various vaccination regimens (one and two vaccinations) conferred complete protection from RVF within 35 days after the first vaccination. Vaccines given 35 days prior to challenge prevented viremia, fever and RVFV-associated histopathological lesions. This study supports the notion, that a recombinant RVFV glycoprotein-based subunit vaccine platform is able to prevent and control RVFV infections in target animals.