Chikungunya

Chikungunya, caused by the mosquito-borne chikungunya virus, is endemic to many regions of the tropics. First discovered in Tanzania, the virus has recently been associated with large outbreaks in South America. CEPI is keen to understand the epidemiology of chikungunya in Africa, an understudied region where the virus remains present. CEPI supported modelling efforts to estimate the global burden of Chikungunya and assess the potential impact of various vaccination strategies. Models were also used to project and quantify the public health and economic benefits of a chikungunya vaccine and CEPI’s 100 Days Mission investment for a Chikungunya-X vaccine in the event of the emergence of Chikungunya X (a hypothetical, novel chikungunya-like virus with pandemic potential). In addition, CEPI’s awardees supported Paraguay during their large outbreak in 2022/2023.

Supporting vaccine development and deployment, CEPI's ACHIEVE study is the largest ever in understanding chikungunya burden in East Africa. For more detail on this study, please see the dedicated page: ACHIEVE

Filoviruses

Filoviruses include Ebola and Marburg virus, which cause sporadic outbreaks across Africa with high fatality rates. CEPI is working to develop multivalent and broadly protective filovirus vaccines. To support trial implementation, we closely monitor any outbreaks that occur, such as the 2024 Marburg virus outbreak in Rwanda. This facilitates rapid response, whereby the window of opportunity for trial implementation is often very short.

Lassa Fever

Lassa fever, caused by the zoonotic Lassa virus, is endemic in West Africa, but data on disease burden, incidence, and risk factors for infection are poorly characterised. Under the Enable programme, CEPI is helping to map the epidemiology of Lassa fever, filling in knowledge gaps to guide upcoming vaccine trials. CEPI is supporting modelling efforts to produce spatiotemporal risk maps for Lassa fever and to estimate the potential impact of routine and reactive vaccination campaigns. Another analysis from a modelling research project funded by CEPI estimated the burden of Lassa fever in West Africa, assessed and quantified the public health benefits and economic impacts of the Lassa fever vaccine and the impact of CEPI’s investments in the 100 Days Mission in the event of a pandemic scenario.

For more detail on the Enable programme please see the dedicated page: Enable Programme

MERS-CoV

MERS-CoV causes infections particularly in the Arabian Peninsula, where people acquire the infection from infected camels. MERS-CoV is also present in other parts of Asia and Africa, wherever dromedary camels reside. Epidemiology is key to understanding the true prevalence and incidence of disease, and monitoring genetic changes (known as molecular epidemiology) in the virus that could make the virus more dangerous to humans, and facilitating the design of future vaccines and trials.

Mpox

Mpox, a zoonotic virus and close relative of smallpox, is endemic in parts of Central and West Africa. The virus has several ‘variants’ (known as clades), and some are associated with wider outbreaks and higher mortality. CEPI is closely monitoring the high incidence of mpox (clade Ib) in the Democratic Republic of the Congo and neighbouring African countries – which now has become a public health emergency of international concern (PHEIC) declared by the World Health Organization. CEPI currently aims to increase our understanding of epidemiology by supporting observational studies and/or real-world evidence generation as well as identifying additional research priorities related to mpox vaccine and explore ways in which modelling activities can be used to address some of the different aspects of transmission and interventions.

Nipah Virus

Nipah virus is associated with sporadic outbreaks in Asia with high case fatality. There are still large knowledge gaps around transmission pathways, risk factors, and differences between clades that are critical in informing medical countermeasure development. Epidemiological studies and methods are needed to fill these knowledge gaps, as well as to rapidly detect cases through robust surveillance systems. Early detection of cases, especially in a Nipah X scenario, underpins the 100-days mission and the fast development and deployment of medical countermeasures. CEPI has commissioned modelling efforts to estimate the burden of Nipah, assess the potential public health impact of using Nipah vaccines for outbreak response, and estimate the associated vaccine demand. More recently, a new project has been approved to determine optimal deployment strategies for Nipah vaccines and monoclonal antibodies (mAbs) through mathematical modelling. Modelling and Simulations are also used to optimise clinical research protocols for Nipah vaccines if Nipah virus acquires greater human-to-human transmissibility.

Rift Valley Fever

Rift Valley fever (RVF) is a viral haemorrhagic disease that infects domesticated animals and humans through insect bites (mosquitoes and flies) or through direct contact with the blood of infected animals. CEPI is looking to improve our understanding of RVF spillover events and outbreaks in humans, which are likely underreported due to poor surveillance, as well as developing an early warning system, and helping to outline clinical risk factors for human disease. Together, these will inform whether RVF vaccine clinical trials are practically feasible. CEPI has commissioned a systematic review of epidemiology studies and modelling projects to estimate the burden of Rift Valley fever, evaluate the potential public health impact of vaccines used for outbreak response, and estimate the associated vaccine demand. More recently, a call for proposals has been launched to support Rift Valley fever epidemiology and modelling efforts, to assist vaccine developers in planning Phase IIb/III clinical trials and engaging in regulatory discussions.

For more detail on activities related to RVF please see the additional Priority Diseases page: Rift Valley Fever