Efficacy of a recombinant Rift Valley fever virus MP-12 with NSm deletion as a vaccine candidate in sheep.
Rift Valley fever virus (RVFV), a mosquito-borne virus in the Bunyaviridae family and Phlebovirus genus, causes RVF, a disease of ruminants and man, endemic in Sub-Saharan African countries. However, outbreaks in Yemen and Saudi Arabia demonstrate the ability for RVFV to spread into virgin territory and thus the need exists to develop safe and efficacious vaccines that can be used outside the endemic zones. Commercial RVFV vaccines are available but have limitations that prevent their use in disease-free countries. Consequently, there are ongoing efforts to develop and/or improve RVFV vaccines with global acceptability. In this study a previously developed MP-12-derived vaccine candidate with a large deletion of the NSm gene in the pre Gn region of the M segment (arMP-12-ΔNSm21/384) developed by T. Ikegami, that was already shown to be safe in pregnant sheep causing neither abortion nor fetal malformation was further evaluated. This vaccine was tested for protection of sheep from viremia and fever following challenge with virulent RVFV ZH501 strain. A single vaccination with arMP-12-ΔNSm21/384 fully protected sheep when challenged four weeks post vaccination, thereby demonstrating that this vaccine is efficacious in protecting these animals from RVFV infection.
National Centre for Foreign Animal Disease, Canadian Food Inspection Agency, Winnipeg, MB, Canada R3E 3M4; Department of Medical Microbiology, University of Manitoba, Winnipeg, Canada.
Hana M
HM
Weingartl
National Centre for Foreign Animal Disease, Canadian Food Inspection Agency, Winnipeg, MB, Canada R3E 3M4. Electronic address: charles.nfon@inspection.gc.ca.
Charles K
CK
Nfon
National Centre for Foreign Animal Disease, Canadian Food Inspection Agency, Winnipeg, MB, Canada R3E 3M4.
Shunzhen
S
Zhang
National Centre for Foreign Animal Disease, Canadian Food Inspection Agency, Winnipeg, MB, Canada R3E 3M4.
Peter
P
Marszal
ABADRU, ARS, USDA, Manhattan, KS, USA.
William C
WC
Wilson
UTMB, Galveston, TX, USA.
John C
JC
Morrill
UTMB, Galveston, TX, USA.
George E
GE
Bettinger
UTMB, Galveston, TX, USA.
Clarence J
CJ
Peters
D000818:Animals; D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D007111:Immunity, Cellular; D007371:Interferon-gamma / Q000276:immunology; D009500:Neutralization Tests; D012367:RNA, Viral / Q000097:blood; D012295:Rift Valley Fever / Q000517:prevention & control / Q000662:veterinary*; D012296:Rift Valley fever virus; D012756:Sheep; D012757:Sheep Diseases / Q000517:prevention & control* / Q000821:virology; D014613:Vaccines, Attenuated / Q000276:immunology; D014765:Viral Vaccines / Q000276:immunology*; D014766:Viremia / Q000517:prevention & control
D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D012367:RNA, Viral; D014613:Vaccines, Attenuated; D014765:Viral Vaccines; D007371:Interferon-gamma
NSm deleted MP-12; Rift Valley fever; Sheep; Vaccine