A novel vaccine approach combining mosquito salivary antigens and viral antigens to protect against Zika, chikungunya and other arboviral infections.

Zika and chikungunya are mosquito-borne viruses with epidemic potential, and both are transmitted by the bite of infected _Aedes_ female mosquitoes. Zika and chikungunya outbreaks have been reported in South and Central America, the Caribbean, the Pacific islands, Africa, and Asia. There is a risk that these viruses will spread geographically by infected travellers and by the expansion of _Aedes'_ habitat due to global warming and deforestation. There is currently no vaccine or antiviral to prevent or treat chikungunya and Zika virus infection and the only protection comes from preventing mosquito bites. _Aedes_ mosquitoes are also carriers of dengue and yellow fever viruses whereas viruses such as West Nile, St. Louis encephalitis, and Japanese encephalitis are mainly transmitted by _Culex_ mosquitoes.

Infected female mosquitoes deposit virus into the skin dermis as they probe for a blood meal to provide the nutrition required to lay fertile eggs. Probing triggers activation of distinct inflammatory pathways in response to mosquito biting and to virus sensing. Whole mosquito saliva contains molecules that help control blood flow but also contains molecules that influence the course of the infection in the host. Immune cells resident in the skin and cells recruited to the bite site are susceptible to infection, hosting the first round of viral replication rather than being the first line of defence. Modifying the immune response to the saliva could translate in reduced viral replication in the skin and dramatically alter the course of the infection.

ConserV Bioscience has designed a two-component vaccine: the first component is common to all _Aedes_ and _Culex_ mosquitoes and aims to stop the beneficial effects that mosquito saliva has on supporting viral infection; the second is a variable component that targets specific regions of viruses carried by mosquitoes. For this project, the focus is on Zika and chikungunya, but this approach could be applied to prevent other mosquito-borne diseases by only requiring a change of target in the second, virus specific component.

The development of a vaccine that is aimed at disrupting the mechanism by which infection becomes established in the body, combined with pathogen specific targets, is highly innovative. This project will focus on the selection of the best antigens for the two vaccine components from an existing list of potential peptide candidates. The best candidates for the two components will be evaluated, separately and combined, for immunogenicity and efficacy against both Zika and chikungunya virus.