Felicity Deeley, Senior Account Executive, Incisive Health
Vaccines and other immunisation products have saved millions of lives globally from previously life-threatening infectious diseases. This World Immunisation Week offers the chance to both celebrate these successes and reflect on how we can capitalise on new innovations in vaccine development to address particularly pressing global health challenges, such as the climate change-associated rise in vector-borne diseases (VBDs).
VBDs, including malaria, dengue, zika, chikungunya, leishmaniasis, and others, are infectious agents transmitted to humans by organisms such as mosquitoes. The disease burden of these diseases is high and has disproportionately impacted low- and middle-income countries (LMICs) in traditionally warmer regions of the globe. Now, the threat posed by VBDs is rapidly escalating due to climate change. [1,2]
Currently, there is a severe dengue epidemic is sweeping across Latin America, placing immense strain on health systems in the region.[3] Brazil, in particular, has experienced a sharp increase in dengue cases, reporting over 1.5 million cases in 2024 so far,[4] and causing several states to declare public health emergencies.[5]
The increase in dengue cases and other VBDs can in part be attributed to rising temperatures and increased precipitation levels associated with climate change, which modify the patterns and intensity of these diseases.[6] The habitat of disease-carrying mosquitoes is also rapidly expanding, with outbreaks now affecting Europe. [7] Cases of locally acquired dengue infections have been reported in France, Italy, and Spain as recently as 2023.[8]
These epidemics and sporadic outbreaks highlight the global nature of this challenge and the potential for the next pandemic to be a VBD.
Vaccines stand as an indispensable tool in the prevention and control of infectious diseases, as highlighted by their role in the COVID-19 pandemic.[9] After decades of slow progress in VBD vaccines, companies are now actively investing in this field.
To ensure the system is ready to grasp the opportunity presented by new vaccines as a tool in the fight against VBDs, there are a number of key actions that must be taken forward by countries and the global community.
Implementing comprehensive community engagement and education programmes can help promote vaccine acceptance. These programs should be evidence-based, culturally sensitive, and tailored to the specific concerns and beliefs of target populations.
Sustained investment in research and development (R&D) for vaccines against neglected VBDs is essential. To support this effort, there's a need for a global initiative that prioritises funding for vaccine R&D. Additionally, countries should persist in their investment of global health initiatives like Gavi, The Vaccine Alliance, and support product development partnerships such as the Drugs for Neglected Diseases Initiative (DNDi) or Medicines for Malaria Ventures
While vaccines are a vital tool, a comprehensive approach to combating the health impacts of climate change and VBDs must also extend beyond immunization. It is important for countries to invest in integrated vector management strategies, including insecticides, environmental interventions, and surveillance and monitoring systems to detect emerging vector-borne threats early. Implementing effective integrated vector management programmes will help strengthen resilience against emerging threats and presents an opportunity for collaboration between public health agencies, environmental organisations, and the private sector.
Ultimately, safeguarding global public health against VBDs necessitates a collaborative and multifaceted approach that integrates vaccination efforts with broader public health initiatives and environmental management strategies. With Brazil assuming the G20 presidency later this year, and South Africa in 2025, there is an opportunity to turn up the volume on the need to prioritise VBD prevention and management, and for governments to demonstrate their commitment to addressing the impact of VBDs amidst evolving environmental challenges.
References
1. WHO, Vector-borne disease, March 2020, last accessed April 2024. Available here
2. Kim et al, Mitigating the effects of climate change on human health with vaccines and vaccinations, October 2023. Available here
3. AP, Dengue is sweeping through the Americas early this year, March 2024, last accessed April 2024. Available here
4. European Centre for Disease prevention and Control, Dengue worldwide overview, last accessed April 2024. Available here
5. Reuters, Dengue spreads fast Brazil promoting emergency health measures, February 2024, last accessed April 2024. Available here
6. London School of Hygiene and Tropical Medicine, Malaria and dengue predicted to affect billions more people if global warming continues uncurbed, July 2021, last accessed April 2024. Available here
7. Climate ADAPT, Climatic suitability for infectious disease transmission – Dengue, last accessed April 2024. Available here
8. European Centre for Disease prevention and Control, Autochthonous vectorial transmission of dengue virus in mainland EU/EEA, 2010-present, last accessed April 2024. Available here
9. Kim et al, Mitigating the effects of climate change on human health with vaccines and vaccinations, October 2023. Available here