Confronting the climate crisis
Advancing science and equity to face surging threats
Dengue infections have doubled year on year since 2021, and half of the world’s population is now at risk of the mosquito-borne climate-sensitive disease. Outbreaks in Latin America, South-East Asia, and Africa made 2024 dengue’s deadliest year on record – overwhelming health systems and causing widespread suffering and disruption in affected communities.
Warmer temperatures are expanding the range of Aedes mosquitoes, increasing their biting frequency, accelerating dengue virus replication within them, and shortening the time it takes for mosquitoes to become infectious after feeding on an infected host. Despite dengue’s growing prevalence, there is still no specific treatment for the disease. Children, pregnant women, and older adults are most at risk of developing life-threatening complications.
There are serious research gaps on the links between climate change and the epidemiology of vector-borne neglected diseases, but growing evidence suggests that shifting temperatures and rainfall patterns are influencing many. The effects are not always due solely to impacts on the insect vectors. In the case of T.b. rhodesiense sleeping sickness, a recent outbreak has been linked to human and animal migration due to heat and drought that bring people and animal ‘reservoirs’, such as cattle, in closer proximity to the tsetse flies that transmit the disease.
Climate change has a disproportionate impact on the poorest and most marginalized communities, exacerbating insecurity and displacement and threatening access to food and clean water. The same communities are also hit hardest by climate-sensitive NTDs. Guarding against these growing threats to vulnerable communities worldwide requires decisive action and sustained investment in R&D for simple, safe, and effective health tools tailored to the needs of patients and the healthcare systems they rely on.
Innovating for climate-sensitive diseases
Through the Dengue Alliance, DNDi has continued our work with leading research institutes in endemic countries to identify and develop dengue treatments that can prevent the development of severe and potentially life-threatening complications. In 2024, the Alliance progressed pre-clinical testing of three host-directed therapies and continued to evaluate broad-spectrum antivirals, with preparations for Phase II and III trials well underway (read more). Together with Alliance partners, we have also completed epidemiological research to better characterize the global burden of disease, develop mechanisms to expedite access to treatments when they become available, and identify biomarkers that can predict progression to severe disease.
PhD student Farah Bary fractionates whole blood – separating it into its component parts using a centrifuge – for dengue studies at the Department of Immunology and Molecular Medicine of the Allergy Immunology and Cell Biology Unit of the Sri Jayawardenepura University in Sri Lanka.
In 2024, the World Health Organization (WHO) updated its treatment guidelines to recommend fexinidazole, developed by DNDi, Sanofi, and partners, as the first-line treatment for T.b. rhodesiense sleeping sickness. Now approved for use in Ethiopia, Malawi, and Zimbabwe – with additional approvals expected soon – the first patients outside of clinical trials are now receiving the new treatment.
Despite this progress, more is needed to confront the warming planet’s impact on health, including new health tools that are safe, accessible, and tailored to patients’ needs. Across our portfolio, our teams and partners are driving scientific progress for the climate-sensitive diseases we are focused on, including dengue, sleeping sickness, leishmaniasis, Chagas disease, mycetoma, and parasitic worms.
Read more about our R&D progress across these climate-sensitive diseases.
Putting medical innovation on the climate change agenda
Standing in solidarity with the most neglected means centring on communities at the frontlines of the climate crisis. In 2024, DNDi continued to speak out for policies and commitments that prioritize R&D for new health tools that can meet their growing needs.
At the 154th session of the WHO Executive Board and the 77th World Health Assembly (WHA) in 2024, we joined Médecins Sans Frontières (MSF) and other civil society partners in advocating for commitments to support R&D for climate-sensitive diseases in the WHA resolution on Climate Change and Health. We urged Member States to invest in R&D for new diagnostics and treatments, promote equitable access to health tools, and establish a prioritized list of climate-sensitive diseases. We welcomed the resolution’s call for Member States to ‘promote research and development to detect, prevent, test for, treat and respond to climate-sensitive diseases and health outcomes, and to support affected communities in their efforts to adapt to the impacts of climate change, by creating an enabling environment to facilitate equitable access to health tools by those hit hardest by climate sensitive diseases and health impacts of climate change’. The commitments were translated into proposed actions in the Global Action Plan on Climate Change and Health, adopted at the 78th WHA in May 2025.
Supporting negotiations with G20 countries and championing the need for equitable access to new health tools for climate-sensitive diseases in the run-up to the Fifth Meeting of the G20 Health Working Group and the G20 Health Ministerial Meeting in October 2024, we welcomed the adoption of the Rio de Janeiro Declaration and creation of the G20 Coalition for Local and Regional Production, Innovation, and Equitable Access. In keeping with G20 Health Ministers’ commitment to enhancing the climate resilience of health systems, we are advocating for the Coalition to focus on dengue therapeutics as a pilot project that can help address the disproportionate impact of the climate crisis on disadvantaged and marginalized communities.
Supporting resilience at the community level
Environmental sustainability and health system resilience at the local level are critical to addressing the climate crisis. In 2024, DNDi conducted an environmental, social health, and safety assessment at clinical trial sites and health facilities in Kenya and the Democratic Republic of the Congo (DRC). We worked with partners to roll out comprehensive training and capacity-strengthening initiatives, including on World Bank Environmental and Social Standards and waste management. At Kacheliba Hospital in Kenya, DNDi supported the construction of green laboratories, eco-friendly hospital wards, and a sustainable kitchen. These investments not only enhance the quality and safety of healthcare delivery but also reduce the environmental footprint of medical facilities, setting a precedent for the development of sustainable health infrastructure in other regions.
More 2024 highlights:
Photo credit: Ana Ferreira-DNDi; Xavier Vahed-DNDi
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