Protective immune responses induced by different recombinant vaccine regimes to Rift Valley fever

• Published in: Vaccine Vol. 24; no. 49; pp. 7181 - 7189
• Main Authors: Wallace, D.B., Ellis, C.E., Espach, A., Smith, S.J., Greyling, R.R., Viljoen, G.J.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 30.11.2006; Elsevier; Elsevier Limited
• Subjects: Animals; Antigens, Viral - biosynthesis; Antigens, Viral - isolation & purification; Applied microbiology; Arboviroses; Bacteria; Biological and medical sciences; Body Temperature - physiology; Cattle; Deoxyribonucleic acid; Disease; DNA; Drug Delivery Systems; E coli; Enzyme-Linked Immunosorbent Assay; Female; Fever; Fundamental and applied biological sciences. Psychology; Glycoproteins; Human viral diseases; Immunization; Immunization Schedule; Immunization, Secondary; Infectious diseases; Lumpy skin disease virus; Male; Medical sciences; Mice; Mice, Inbred BALB C; Microbiology; Miscellaneous; Recombinant vaccine; Rift Valley Fever - immunology; Rift Valley Fever - prevention & control; Rift Valley Fever - veterinary; Rift Valley fever virus; Rift Valley fever virus - immunology; RNA, Viral - immunology; Sheep - immunology; Sheeppox virus; Skin diseases; Studies; Tropical viral diseases; Vaccines; Vaccines, antisera, therapeutical immunoglobulins and monoclonal antibodies (general aspects); Vaccines, DNA - administration & dosage; Vaccines, DNA - therapeutic use; Vaccines, Synthetic - administration & dosage; Vaccines, Synthetic - therapeutic use; Vector-borne diseases; Viral diseases; Viral Vaccines - administration & dosage; Viral Vaccines - therapeutic use; Virology; Yemen; Rift Valley fever virus; Sheeppox virus; Lumpy skin disease virus; Recombinant vaccine; Rift valley fever; Immunoprotection; Chordopoxvirinae; Sandfly fever group virus; Vaccine; Rift valley fever virus; Infection; Virus; Bunyaviridae; Poxviridae; Capripoxvirus; Viral disease; Arbovirus disease; Veterinary; Phlebovirus
• ISSN: 0264-410X; 1873-2518
• DOI: 10.1016/j.vaccine.2006.06.041

The glycoprotein (GP) and nucleocapsid (NC) genes of Rift Valley fever virus (RVFV) were expressed in different expression systems and were evaluated for their ability to protect mice from virulent challenge using a prime-boost regime. Mice vaccinated with a lumpy skin disease virus-vectored recombinant vaccine (rLSDV–RVFV) expressing the two RVFV glycoproteins (G1 and G2) developed neutralising antibodies and were fully protected when challenged, as were those vaccinated with a crude extract of truncated G2 glycoprotein (tG2). By contrast mice vaccinated with a DNA vaccine expressing G1 and G2 did not sero-convert with only 20% of them surviving challenge. Mice vaccinated with the DNA vaccine and boosted with rLSDV–RVFV also failed to sero-convert but 40% survived challenge. Surprisingly, although none of the mice immunised with the purified NC protein sero-converted, 60% of them survived virulent challenge. The rLSDV–RVFV construct was then further evaluated in sheep for its dual protective abilities against RVFV and sheeppox virus (SPV). Vaccinated sheep sero-converted for both viruses and were protected against RVFV challenge, however, neither the immunised or negative control animals showed any significant reactions to the virulent SPV challenge.