Through reverse genetic engineering, scientists at St Andrew’s University, Scotland, have developed a modified, attenuated, bi-segmented version of the Rift Valley Fever Virus (RVFV) which replicates in cell culture and is immunogenic.
They say the technique has broad applications across the Bunyavirus family and provides a platform for developing novel attenuated virus vaccines to a range of viral zoonotic diseases. Attenuated vaccine virus cannot revert to virulence in the presence of wild type, as successful re-assortment cannot occur between the genetically modified bi-segmented vaccine virus and tri-segmented wild type strains.
The recombinant RVFV is genetically distinct from wild type and other live and killed vaccine viruses, so is distinguishable from these and promotes an immune response allowing differential diagnosis.
This will provide a live-attenuated RVFV as the basis for a novel vaccine against the infection, which is transmitted by mosquitoes and affects both humans and animals
The attenuated virus has a bi-segmented genome allowing differentiation from wild type and existing vaccine viruses. It is also tagged, to attenuate the virus in cell culture systems but allows similar growth properties to parental virus.
The technique has wide application across the Bunyaviridae virus family, with present laboratory work ongoing in St Andrews on RVFV. The technique provides a platform to genetically modify all the members of this tripartite-genome family and potentially produce diagnostically distinguishable live-attenuated vaccines for use in animals and humans against RVFV and other viral zoonotic diseases.
The technique for engineering a viable bi-segmented genome in Bunyaviridae is subject to a UK patent application filed in 2010; UK patent application number 1001726.7.
For more information, visit the project’s page at: http://www.university-technology.com/details/attenuated-bi-segmented-bunyavirus-vaccine