Preventing West Nile Virus in Europe
Currently, there is no vaccine available to protect humans against WNV infection. The EU-funded WINGS proposal aimed to develop tools for the control and prevention of one of the most threatening vector-borne emerging diseases. The goal of the WINGS investigators was to identify the most potent antigen (target) and develop immunisation strategies against rapidly adaptable, newly emerging WNV strains. During the three years of the project, the scientific team analysed several proteins that form the viral envelope of the European strain and cloned the most relevant genes for vaccine development and biomarker assays. They tested protein vaccine/adjuvant combinations using animal models and selected the most potent ones. Another approach to immunisation against WNV utilised DNA-based vaccination. This approach relies on the ability of the organism to propagate the vaccine inside the body in response to the immunisation. The scientists used nanoparticles to enhance the delivery of the DNA and to prolong the half-life of the vaccine antigen inside the human body. The consortium successfully developed several candidate vaccines consisting of either recombinant proteins or DNA, or a mixture of both. The most promising vaccine candidate showed long-lasting complete protection in mice and non-human primates. The vaccine was well tolerated, protective against different circulating European WNV strains, and displayed high immunogenicity and protective capacity. In addition, as the most promising candidate is based on a recombinant protein expressed in bacteria, the vaccine can be produced in high yields. In addition, researchers developed several tools for the specific diagnosis of WNV infection. A novel method enables the detection and isolation of WNV from urine samples. This is a significant advantage over existing protocols because of its higher sensitivity in comparison to blood sample testing. In sum, the WINGS project delivered several novel technologies and tools to specifically detect and efficiently counteract the WNV threat. These efforts delivered valuable data about WNV biology, and prepare Europe for its potential spread.
Keywords
West Nile Virus, emerging diseases, vaccine, recombinant proteins
