Arboviruses

Arboviruses are viral vector-borne diseases (i.e. viruses transmitted by insect vectors) and represent a major economic and health burden for both human and animal populations. Our research in this area focusses on the most significant family of arboviruses - the flaviviruses - specifically, dengue, yellow fever and zika:

• Dengue is the most common mosquito-transmitted viral infection in humans. Our research focuses on the development and deployment of control measures, notably vaccines and Wolbachia, a novel biological control to reduce the ability of mosquitoes to transmit dengue. Work undertaken by the groups of Neil Ferguson and Christl Donnelly are informing the design of the first large-scale trials of Wolbachia which will measure its impact on dengue transmission. The first such trials are likely to start in Colombia and Indonesia, with studies in Vietnam and Brazil starting soon after. In addition, Neil Ferguson's group has played a major role in modelling the likely public health impact of the Sanofi vaccine, informing WHO recommendations on its use. Most recently, the group started to work with US colleagues to develop the first global maps of dengue transmission intensity. This work is relevant to refining assessments for disease burden and to predicting the impact of both the Sanofi vaccine and novel vector control methods.
• Yellow fever continues to be a significant cause of disease burden in sub-Saharan Africa, and, to a lesser extent, Latin America. Tini Graske and colleagues are working closely with WHO and GAVI (the Global Vaccine Alliance) to refine estimates of the global disease burden from yellow fever and the impact of vaccination campaigns. This work is informing GAVI's Vaccine Investment Strategy. In addition, last year, the group supported WHO in responding to an epidemic outbreak in Angola, the largest outbreak in 30 years. In the face of global vaccine shortages, a key priority has been to estimate populations at risk from the Angola outbreak in order to inform dose-sparing vaccination strategies.
• Zika has risen to prominence in the last two years as a result of the large epidemic which swept across Latin America. Our research has focussed on better understanding the epidemiology of this little-studied virus. In work published in 2016, we suggested that the ongoing Latin American Zika pandemic may have now peaked, limiting scope for interventions having a major impact. This work also highlighted that the current pandemic will generate high levels of herd-immunity in the countries affected, preventing future large-scale outbreaks for at least a decade. This gives a valuable window to develop vaccines and novel vector controls, but poses challenges for the design of efficacy trials. In addition,  we are conducting serological surveys in Colombia with local collaborators to better characterise the epidemiology of the Latin American Zika epidemic.

Work across these three diseases shares a number of commonalities - most notably, our focus on elucidating the demographic and climatic drivers of transmission, characterising spatiotemporal hetergeneity in transmission intensity and understanding patterns of disease persistence. To achieve such a broad scale of activities, we collaborate with numerous public health agencies (e.g. WHO, CDC, GAVI) and fellow researchers around the world. Our research is funded by the Bill and Melinda Gates Foundation, the US National Institutes of Health and the MRC.