Scientists warn ‘forever chemicals’ could limit effectiveness of COVID-19 vaccines
Exposure to a group of substances known as “forever chemicals” could hinder how some respond to the COVID-19 vaccine, scientists said Thursday.
Jamie DeWitt, an East Carolina University toxicologist, said research has shown that exposure to per- and polyfluoroalkyl substances (PFAS) leads to immune system suppression. That could pose a challenge for vaccines that are widely seen as critical to ending the COVID-19 pandemic, including across a wide swath of North Carolina.
“The vaccine is going to be effective based on its formulation,” DeWitt said. “What PFAS affect is the body’s ability to make antibodies against the vaccine.”
The scientists spoke during a press briefing by the Environmental Working Group, an environmental nonprofit that researches drinking water pollution and toxic chemicals.
Researchers have found that more than a million people along the Haw and Cape Fear Rivers are exposed to PFAS through their drinking water. Along the Haw, from researchers believe wastewater treatment plants’ sludge containing PFAS is contributing to the contamination after it is sprayed onto fields. On the Cape Fear, there is lingering contamination from Chemours’ Fayetteville Works plant, as well as chemicals flowing from the Haw.
There are thousands of PFAS, some of which have been linked with health effects including some cancers, thyroid disease and high cholesterol. The chemicals are used in a wide variety of items from carpets to rain coats to pizza boxes because they are grease- and water-resistant.
“These chemicals are persistent and accumulative, but they are also mobile, so in fact they are all over the world,” Linda Birnbaum, the former director of the National Institute for Environmental Health Sciences, said during Thursday’s briefing.
Every PFAS that has been studied impacts the immune system, DeWitt said, either making it overly active or suppressing it. That can impact vaccine response, DeWitt said, a process scientists believe could happen when PFAS stop a process that allows cells to transform into the kind that send antibodies out.
“In some people, the immune system just doesn’t make the amount of antibodies they need to make the response to the vaccine effective,” DeWitt said.
There are not yet any published studies specifically looking at how PFAS could affect the body’s response to the COVID-19 vaccine, but scientists have found decreased response to diphtheria, measles and tetanus vaccinations.
“The risk is real,” DeWitt said, “but we can’t put definitive numbers on those risks right now.”
People who are exposed to PFAS would still get some benefit from vaccines, Birnbaum added, just one that may be less significant than someone with lower levels of PFAS in their system. She suggested that a potential workaround could be to provide additional vaccine to places where there is known exposure to PFAS.
“Instead of getting that one booster that’s now required with the two mRNA vaccines ... maybe you would need a third (shot),” Birnbaum said, referring to the Pfizer and Moderna vaccines.
North Carolina received 85,800 doses of the Pfizer vaccine this week and expects to receive 61,000 more next week, The News & Observer has reported. If the Food and Drug Administration grants an emergency use authorization for Moderna’s vaccine, a step an advisory panel recommended Thursday, the state expects 175,000 doses.
Right now, the Pfizer vaccine is going to hospitals and being used to vaccinate medical personnel and staff who work with COVID-19 patients. If the Moderna vaccine is approved, about half of next week’s doses would go to nursing homes and long-term care facilities, where it would be used to vaccinate residents and staff.
The Centers for Disease Control and Prevention’s Agency for Toxic Substances and Disease Registry is investigating the link between PFAS and COVID-19, Director Robert Redfield said in a Nov. 6 letter to Rep. Daniel Kildee, a Michigan Democrat.
As part of a study investigating COVID-19 among health care personnel and first responders, Redfield wrote, scientists will investigate whether people with higher levels of PFAS in their blood serum make fewer antibodies in response to the COVID-19 vaccine or have a response that wears off more quickly.
Researchers will also investigate whether people with elevated levels of PFAS face increased risks from COVID-19.
A study conducted by researchers in Denmark found that one PFAS, PFBA, was associated with a more severe course of COVID-19. The study is in the preprint phase, meaning it has not yet been peer reviewed.
PFAS have been associated with higher likelihood of diabetes, obesity and asthma, Birnbaum added, conditions which can also make it more dangerous to contract COVID-19.
“If you live in an area with known concentrations of PFAS,” DeWitt said, “be even more diligent about washing your hands, wearing your mask and social distancing.”