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Unveiling the Lesser-Known Impact of Climate Change: The Rise of Mosquito-Borne Diseases

Author: Juan Carlos Jaramillo, MD. Chief Medical Officer, Valneva and Vice President, Vaccines Europe

Climate change is a widely recognized global issue, with far-reaching consequences on weather patterns, sea levels, and temperatures1. However, its impact extends beyond these visible aspects. In this blog post, we shed light on a lesser-known consequence of climate change: the increasing prevalence of deadly mosquito-borne diseases.

The Mosquito Menace
Mosquito-borne diseases are infections transmitted to humans through the bite of a mosquito carrying a virus or parasite2. While there are over 3,000 mosquito species worldwide, it’s alarming to realize that just two species – Aedes aegypti and Aedes albopictus mosquitoes – are responsible for transmitting the most common diseases including dengue, chikungunya, Zika, and yellow fever3.

Historically, these mosquitoes predominantly inhabited tropical and subtropical regions like South America and Southeast Asia4. However, due to rising global temperatures and increased rainfall, these disease-carrying mosquitoes have expanded their reach. In recent years, they’ve infiltrated previously unaffected areas, such as Southern Europe and the United Kingdom5, placing additional strain on healthcare systems across the globe.

The Growing Threat
Currently, mosquito-borne diseases infect up to 700 million people each year6. If current climate change trends persist, projections suggest that as many as 8.4 billion people could be at risk of contracting these diseases by the end of the century7. This represents a substantial public health threat that governments worldwide must address and prepare for.

Valneva’s Commitment
At Valneva, our mission is to contribute to a world where no one dies or suffers from a vaccine-preventable illness. It is this 
vision that drives us to develop vaccines aimed at protecting people from infectious diseases for which no other vaccines or effective treatments currently exist. Scientific innovation is our ally in the battle against disease, a fight that is intensifying 
alongside climate change.

  1. United Nations (2020). Causes and Effects of Climate Change. Available at:
  2. World Mosquito Program. Mosquito-borne diseases. Available at: diseases#:~:text=Common%20types%20of%20mosquitoborne%20diseases%20include%20malaria%2C%20dengue%2C,present%20in%20a%20similar%20way%20to%20dengue%20fever
  3. World Mosquito Program. Explainer: How climate change is amplifying mosquito-borne diseases. Available at:
  4. Kraemer MU, et al (2015). The global distribution of the arbovirus vectors Aedes aegypti and Ae. albopictus. Elife. pp.4.
  5. APHA Science Blog. Johnson, N (2023). What is all the buzz about mosquitoes? Available at:
  6. Qureshi, A (2018). Chapter 2 – Mosquito-Borne Diseases. Academic Press. pp.27–45.
  7. World Economic Forum (2023). As climate change boosts mosquito-borne diseases, we must take action to stop their spread. Available at: