How “forever chemicals” might impair the immune system
Carolyn Beans
Abstract
Researchers are exploring whether these ubiquitous fluorinated molecules might worsen infections or hamper vaccine effectiveness . Animal models and human studies suggest that forever chemicals, delivered through water, food, and air, alter the immune system, potentially diminishing our ability to fight disease or respond to a vaccine. Image credit: Shutterstock/Dmitry Naumov. Stain-resistant carpets and nonstick pots were once the epitome of “better living through chemistry,” their space-age properties conferred by molecules known as perfluoroalkyl and polyfluoroalkyl substances (PFAS). But in the early 2000s, researchers began to discover that PFAS were somehow reaching the farthest corners of the planet—from polar bears in Alaska (1) to pilot whales in the Faroe Islands of the North Atlantic (2). These molecules contain chains of carbon peppered with fluorine atoms, which together form one of the strongest known chemical bonds. That helps these chemicals excel at repelling grease and water but also makes them astonishingly resistant to degradation in the environment (3). Amid a flurry of new studies, scientists are still figuring out what risks these ubiquitous “forever chemicals” pose to public health (see “PFAS Politics”). Epidemiologists and toxicologists point to myriad possible consequences, including thyroid disease, liver damage, and kidney and testicular cancers (4). Impacts on the immune system are a particular concern. Animal models and human studies have provided strong evidence that PFAS alter the immune system, diminishing the ability to fight disease or respond to a vaccine. These studies have heightened urgency as nations across the globe grapple with the coronavirus disease 2019 (COVID-19) pandemic and engage in a vaccination campaign of historic proportions. Researchers are intent on better understanding how PFAS affect coronavirus and other infectious diseases—as well as the vaccinations meant to stymie them. But many questions remain: Scientists don’t know the toxicity levels of most PFAS or how …