An emerging global health threat: climate change’s impact on infectious diseases

This is a guest post, kindly authored by Dr Juan Carlos Jaramillo, Chief Medical Officer, Valneva, and Vice President, Vaccines Europe.

Climate change is one of the biggest global challenges of current times. From rising sea levels to increasing temperatures and heatwaves, the effects of climate change on our physical environment are increasing in scale, frequency and intensity.¹ However, according to the World Health Organization¹, climate change also presents a fundamental threat to human health, notably by augmenting the risk of infectious diseases.

The Rise of Infectious Diseases

Climate change impacts our health both indirectly (e.g. respiratory diseases linked to pollution) and directly (e.g. flooding and hurricanes can cause injury or death).² Infectious diseases are also influenced by climate changes. Warmer temperatures can affect the geographical distribution of infectious diseases and, for some, extend the transmission periods.³

In particular, the spread of mosquito-borne diseases presents a growing challenge. Currently, mosquito-borne diseases infect up to 700 million people worldwide each year,⁴and mosquitoes have now become the deadliest creatures in the world because of the many diseases they can transmit.⁵ Common types of mosquito-borne diseases include malaria, dengue, chikungunya, West Nile virus, yellow fever and Zika.⁶ Historically, the mosquitoes which carry these diseases have predominantly inhabited tropical and subtropical regions,⁷ such as Central and South America, sub-Saharan Africa, and Southeast Asia.

However, these disease-carrying mosquitoes have expanded their reach due to extreme climate and weather patterns.⁷ In recent years, previously unaffected areas, such as Southern Europe and the United Kingdom, are also facing an increased risk of these diseases⁸ and a spike of incidence was also recorded in the United States in 2023.⁹

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 century.¹⁰

This presents a stark reality which underscores the urgent need for proactive measures to mitigate climate change and its impact on public health. Current approaches to disease prevention must also evolve to address the complex relationship between climate change and infectious diseases – this includes continued advancements in vaccine development.

Valneva’s Ongoing Commitments

At Valneva, we remain driven by scientific innovation. Our vision is to live in a world where no one dies or suffers from a vaccine-preventable illness. This vision empowers us to develop vaccines aimed at protecting people from infectious diseases for which no other vaccines or effective treatments currently exist. While we can’t reverse the impact of environmental changes that have already taken place, our commitment to advancing unique new vaccines means we can be part of the solution, by helping reduce the impact of infectious diseases fuelled by climate change.

We also want to continue raising awareness amongst key stakeholders about the threat of infectious diseases as this public health challenge increases in prominence. We’re looking forward to being part of conversations on this topic at this year’s World Vaccine Congress US, where Valneva will take part in a panel discussion on the efforts towards eradicating chikungunya alongside representatives of the Coalition for Epidemic Preparedness Innovations (CEPI), the Pan American Health Organization (PAHO) and the International Vaccine Institute (IVI). Valneva will also moderate an interactive roundtable focusing on the emerging threats of Zika and chikungunya.

As a global company, we also take every opportunity to continuously improve our sustainability model. From the production line to our support functions, we are all actively working to reduce our carbon footprint, lower the consumption of energy and natural resources, and limit the creation of waste.

Creating a Safer Future for All

The battle against infectious diseases is one which is intensifying alongside climate change. While we continue to make both scientific and environmental efforts, we also call for greater action and collective responsibility from governments and communities worldwide to help slow down the effects of climate change. Without decisive action, we risk facing unprecedented global health challenges that could have far-reaching consequences.

It’s becoming ever-more crucial that we work together to make change, ultimately creating a healthy and safer world for future generations.

We’re thrilled that Dr Juan Carlos Jaramillo and the Valneva team were able to share insights with us before the Congress next week, and look forward to hearing more then! Don’t forget to subscribe to our newsletters here for guest posts and insights to come!