A simple, multivalent vaccine to prevent Zika and Chikungunya: progression and readiness to phase II trial

The aim of this project is to progress the clinical development of a new bivalent vaccine that judiciously induces simultaneous protection against Zika and chikungunya viruses (ZIKV and CHIKV). These two diseases are transmitted by the same mosquito specie as dengue, therefore causing a severe disease burden in the same geographical regions and in the same populations, particularly in low-and-middle-income countries. There is currently no vaccine to prevent Zika or chikungunya infections, and while any one vaccine would be particularly useful to reduce the disease burden in these vulnerable populations, a bivalent vaccine would further support global health by simplifying vaccination campaigns at lower costs when compared to single vaccine campaigns. Infection by ZIKV is a major concern worldwide due to causing neurologic conditions, such as Guillain-Barré syndrome and a 20-fold increase in the incidence of neonatal microcephaly. Infection by CHIKV results in a flu-like symptomatic disease in approximately three quarters of infected people, and may lead to painful and debilitating long-term arthritis in patients of all ages. Persistent arthritis may last for years causing disability and inability to work. Long-term sequelae and lack of specific treatment for ZIKV and CHIKV infections contribute to poverty and high costs for families and governments in areas where the health system is weak and already overwhelmed by other arbovirus diseases such as dengue or by unrelated outbreaks such as SARS-CoV-2\. Socioeconomical factors such as poverty and migration, together with climate change, increase the geographical regions where the mosquitoes live and transmit the viruses. A major breakthrough and an ideal preventive solution would be to provide a bivalent vaccine to simultaneously fight Zika and chikungunya. This proposal aims to leverage the findings and samples collected during a Phase Ib trial that has been completed in Mexico, where both diseases are prevalent. This 12-month project will enable the partners to advance the technical tools and collaborations ready for a phase IIb clinical trial.