Vaccination, a solution to climate change’s health impacts?

How climate change effects our health

There are 15 metrics for measuring the impact of climate change on our human health according to the Lancet Countdown¹Lancet Countdown. (2025, 19 mars). 2024 Report – Lancet Countdown. https://lancetcountdown.org/2024-report/ on health and climate change. They are broken down into four categories: heat related health impacts, extreme weather, changing patterns to infectious diseases, and food impacts. Rising temperatures can cause heat stress, which on its own can cause heat exhaustion, heatstroke, and even death²Hot weather and heat extremes: health risks, Ebi, Kristie L et al. The Lancet, Volume 398, Issue 10301, 698 – 708, but will also stress the cardiovascular and respiratory systems as well as the kidneys. Heat induced inflammation can exacerbate COPD (chronic obstructive pulmonary disease) and even induce chronic kidney disease (26 million cases and counting). Heat waves also cause an increase in West Nile infections.³Thomson, M. C., & Stanberry, L. R. (2022). Climate Change and Vectorborne Diseases. New England Journal Of Medicine, 387(21), 1969‑1978. https://doi.org/10.1056/nejmra2200092

Figure 1: Number of people living with chronic kidney disease attributable to heat stress during the year 2020⁴Heat at work: Implications for safety and health, figure 5, https://www.ilo.org/sites/default/files/2024-07/ILO_OSH_Heatstress-R16.pdf. 

Extreme weather, especially flooding, introduces more water contamination. In a study published on storm related waterborne infections in the United States, Legionnaires’ disease, E. coli, and cryptosporidiosis all increase with heavy rainfall.⁵Lynch, V. D., & Shaman, J. (2023). Waterborne Infectious Diseases Associated with Exposure to Tropical Cyclonic Storms, United States, 1996–2018. Emerging Infectious Diseases, 29(8). https://doi.org/10.3201/eid2908.221906 Additionally, rising water temperatures is bringing Vibrio bacteria to higher latitudes, increasing the danger of contaminated seafood as far North as the Baltic Sea.⁶European Food Safety Authority. (2024, 23 juillet). Vibrio bacteria in seafood : increased risk due to climate change and antimicrobial resistance. European Food Safety Authority. https://www.efsa.europa.eu/en/news/vibrio-bacteria-seafood-increased-risk-due-climate-change-and-antimicrobial-resistance Other infectious diseases are also seen expanding with increasing temperatures. These diseases are vector borne, transmitted by mosquito or tick, and the global temperature rise is driving diseases like Dengue, Zika, and Lyme disease into new territories⁷Thomson, M. C., & Stanberry, L. R. (2022b). Climate Change and Vectorborne Diseases. New England Journal Of Medicine, 387(21), 1969‑1978. https://doi.org/10.1056/nejmra2200092. Air pollution increases with fires and drought. This pollution also stimulates proinflammatory responses that when left uncontrolled can drive the development of autoimmune conditions.⁸Lee, A. S., Aguilera, J., Efobi, J. A., Jung, Y. S., Seastedt, H., Shah, M. M., Yang, E., Konvinse, K., Utz, P. J., Sampath, V., & Nadeau, K. C. (2023). Climate change and public health. EMBO Reports, 24(4). https://doi.org/10.15252/embr.202356821 The most obvious is the increased geographic range for ticks and mosquitos, introducing vector borne diseases, such as Dengue and Lyme disease, into new territories.

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Is there a vaccine for that?

For many of the vector borne diseases, vaccines are feasible. West Nile vaccines are already marketed in the veterinary space. While Phase 2 human trials were promising, especially the trials conducted by Sanofi, large scale Phase 3 trials are a significant roadblock to bringing such vaccines to the market⁹Gould, C. V., Staples, J. E., Huang, C. Y., Brault, A. C., & Nett, R. J. (2023). Combating West Nile Virus Disease — Time to Revisit Vaccination. New England Journal Of Medicine, 388(18), 1633‑1636. https://doi.org/10.1056/nejmp2301816. More innovative clinical trial designs are needed to ensure such vaccines are available to mitigate the effects of climate change.

For Dengue and Lyme disease, the news is better. Takeda’s recently approved Dengue vaccine, Qdenga,  (approved in 2024) has already been employed to help curb a massive Dengue outbreak in Brazil, absorbing all the supply of the vaccine for the first two years of production¹⁰https://www.science.org/content/article/dengue-raging-brazil-promising-local-vaccine-least-year-away. This raises some interesting policy questions about whether climate change related infectious threats should be rolled into the pandemic preparedness schemes developed in response to the COVID-19 pandemic.

Finally, a Lyme disease vaccine in Phase 3 trials, developed by Valneva, in partnership with Pfizer. The vaccine could be authorized as early as 2026¹¹Pfizer and Valneva Complete Recruitment for Phase 3 VALOR Trial for Lyme Disease Vaccine Candidate, VLA15 – Valneva. (2023, 5 décembre). Valneva. https://valneva.com/press-release/pfizer-and-valneva-complete-recruitment-for-phase-3-valor-trial-for-lyme-disease-vaccine-candidate-vla15/. The trial is being conducted across the US and Europe where Lyme disease is highly concentrated. Vaccine developers and health authorities should work together to consider what other vaccines should be developed in anticipation of climate change related shifts in infectious patterns or burdens.

Can we reverse the damage done by climate change on health?

For those suffering from autoimmune diseases brought about by climate related inflammation, the damage has already been done. But that does not prevent vaccines from providing some relief. A new type of therapeutic vaccine, called an inverse vaccine, is on the horizon, which can reverse autoimmune diseases by removing the immune response that are driving the pathology. The first proof of concept for this innovative technology is more than 15 years old, but the technology is enjoying a resurgence with several prominent companies like Pfizer, Bristol Myers Squibb, Novartis, Roche and Boehringer Ingelheim already making investments.

We at Alcimed are here to support you as you determine how climate related vaccines and other therapies could impact your R&D pipeline and other investments. Should you have questions or projects on such projects, do not hesitate to contact our team!

About the author,

Danna, Great Explorer in Infectiology and Immunology in Alcimed’s Life Sciences team in France.