Climate Change is a Direct Threat to Human Health and Immunology
Climate change impacts every disease, every organ system, and every sector of the world’s population, according to scientists and experts in a July 28 program sponsored by Michelson Philanthropies. Additionally, those who contribute the least to greenhouse gas emissions suffer the most negative health impacts.
Produced by the American Association for the Advancement of Science, the webinar focused on the threat climate change poses to the human immune system and featured Dr. Gwen W. Collman from the National Institute of Environmental Health Sciences, Dr. Marcelo Korc from the Pan American Health Organization, and Dr. Sheri Weiser from UC San Francisco. The panel was moderated by Dr. Sean Sanders of Science/AAAS. Watch the full webinar here.
Michelson Philanthropies and Science are also partnering to launch the Michelson Philanthropies & Science Prize for Immunology. The international prizes consist of a $30,000 grand prize and a $10,000 runner up award for recent transformative research by scientists 35 years of age or younger that will have a significant impact on vaccine and immunotherapy development with trans-disease applications. The deadline to apply is October 1.
“It has now become more than apparent that the human immune system is involved in almost all human disease,” said Dr. Gary K. Michelson, founder and co-chair of Michelson Philanthropies. “Whatever your area of research, and regardless of your nominal field of study, if it relates to the immune system—and almost all medical research does—we are interested in you.”
“Harnessing the immune system, including the development of new vaccines, will be critical to mitigate the negative health impacts of climate change.”
Dr. Wayne C. Koff
“Climate change is not just a future threat,” said Dr. Wayne C. Koff, president and CEO of the Human Vaccines Project, which coordinates the Michelson Prizes, annual $150,000 research grants for early career investigators focusing on immunology and vaccine research, including a focus on climate. “For our global health, it’s already a harmful reality with a profound effect on the human immune system. Harnessing the immune system, including the development of new vaccines, will be critical to mitigate the negative health impacts of climate change.”
Climate change also affects food insecurity in many ways, including crop loss from drought and flooding from rising sea levels. Weiser pointed out that climate change can also alter the nutrient content in food as well as the quality and safety of food and water, not to mention the economic impacts of climate change such as poverty and unemployment.
“And on top of all that, we see that the stability of the entire food system is in question because of rising food prices, political instability, and conflict brought about by food insecurity,” Weiser said. “Food insecurity is a very important driver of migration. Both food insecurity and migration have lots of negative health impacts.”
Weiser has been researching the impacts of food insecurity on the HIV cascade of care for many years and she found that food insecurity negatively affects people from disease acquisition to death.
“It drives chronic disease and poor mental health,” she said. “Migration also has a host of negative health impacts from infectious disease outbreaks to increased risk of gender-based violence and sexually transmitted infections to chronic disease because of lifestyle and diet changes. And all of these things interconnect to worsen health in many different disease categories.”
Collman pointed out the increasingly extreme weather events related to climate change, such as hurricanes, wildfires, floods, and drought. Part of the solution to mitigate the impacts of those events involves being prepared ahead of time.
“Making sure people have access to food and communities can be prepared with food banking and distribution services is part of the research and implementation programs that we should be developing, both in the United States and around the world, in order to reduce the health impacts that we know will come from these weather events,” Collman said.
These extreme weather events, in addition to human activity, are altering soil biodiversity, Weiser added, which in turn has a negative effect on human microbiomes.
“There are risks of all sorts of diseases from an altered microbiome, such as autoimmune diseases and other inflammatory diseases, cardiometabolic and even neurologic, and mental health problems because of the activation of our immune system,” she said.
“If we’re thinking about how climate change affects the immune system, there are the direct impacts including heat stress, wildfires, UV radiation, and there’s a lot of literature on how air pollution blunts immune responses. All of those things could directly blunt our immune response.”
Dr. Sheri Weiser
Collman said these viruses and bacterial agents can also change and become more transmissible to humans. She added that climate change results in a “complicated and complex web of causes” and wondered which comes first.
“Climate affects food and security, and security affects population mobility and demography,” she said. “And we also have to remember that there are vulnerable parts of our population: pregnant women, young children, the elderly. When we talk about people who are most impacted by climate change in any area, no matter what your socio-economic status is, no matter whether you’re in a high-income country or a low-income country, these are vulnerable groups that we have to both study and protect. We have to make sure that they have appropriate services if they are impacted by a negative climate event.”
Korc agreed that infectious diseases and climate change are connected. He credited the environmental movement with encouraging data sharing between governments related to the environment and health.
“That’s a major step, because if there’s no dialogue between the environment sector and the health sector, what can we expect?” he said. “Within the health sector, in the effort to control and prevent infectious diseases, the word ‘environment’ is very seldomly mentioned. They don’t have that integrated approach. So first we need to start in our own home, in the health house. And from there we can have a good understanding to move forward, and to work together with the environment sector. Otherwise, we’re going to fail.”
Collman pointed out that it’s encouraging that young people in particular are interested in the intersection of climate and health.
“It took many years of fundamental research to understand coronaviruses and if that work had not been done in the past, we would never have been able to quickly create effective vaccines to the current SARS-CoV-2 issue. It’s important to understand disease patterns and start development processes for vaccinations as well as treatments. We need to be able to move quickly when we see something coming on the horizon.”
Dr. Gwen Collman
“Our youth, even as young as high schoolers, have embraced climate change as the challenge of their lifetime,” she said. “We see doctoral students, master’s students, and people who are in the early stages of their career who are very interested in this.”
In addition to climate change’s direct impacts on human physiology, there are also mental health impacts.
“Just to give a specific example from our research, we’ve looked at the impact of food insecurity on inflammation gut microbial translocation and immune activation in HIV-infected people,” Weiser said. “Another huge impact of climate change is tons of stress, and we’re seeing that in our own research in Kenya. We know chronic psychological stressors are a huge impact of climate change. That in turn then stimulates our neuroendocrine systems and responses to release cortisol, blunting our immune system.”
Weiser said that climate change also directly impacts human immunology.
“If we’re thinking about how climate change affects the immune system, there are the direct impacts including heat stress, wildfires, UV radiation, and there’s a lot of literature on how air pollution blunts immune responses,” she said. “All of those things could directly blunt our immune response. And we saw this very vividly during the COVID pandemic.”
Populations living in the most polluted regions had the highest rates of COVID cases and the highest COVID-related mortality rates, according to Weiser, representing a direct line from climate change to human health and immunology.
Collman argued that preparation was again the key to preventing the pandemic from becoming even worse than it was.
“Within the health sector, in the effort to control and prevent infectious diseases, the word ‘environment’ is very seldomly mentioned. [We need an] integrated approach.”
Dr. Marcelo Korc
“It took many years of fundamental research to understand coronaviruses and if that work had not been done in the past, we would never have been able to quickly create effective vaccines to the current SARS-CoV-2 issue,” Collman said. “It’s important to understand disease patterns and start development processes for vaccinations as well as treatments. We need to be able to move quickly when we see something coming on the horizon so that we’re ready to be able to put these public health promotion type programs in place and we don’t get to the numbers of deaths that we’ve seen across the world with COVID.”
Weiser added that robust public health infrastructure and social safety net infrastructure must be built to enable people to get access to food, housing, and unemployment benefits that would have, for instance, allowed people to social distance more effectively during COVID.
“We also need to build health system resilience, enable health system preparedness, and activate the health system to be ready for climate health emergencies, so that our hospitals won’t close and are resilient,” she said.
Finally, Weiser added that the next generation of health professionals need to be trained on the links between climate change and health, which she argued is not being done well enough right now.
To that point, “Climate Change and Human Immunology” is one of the topic areas for research proposals for the 2021 Michelson Prizes (the other topic is “Human Immunology and Vaccine Research”). Researchers submitted their work—which aims to expand our understanding of the potential effects of climate change on immune function with a particular interest in research that will directly translate into vaccine and immunotherapy development to mitigate its impact—for consideration to be awarded the $150,000 research grants, which will be announced later this year.