Do PFCs reduce vaccine effectiveness? The dangers they pose are not fully known, but they’re everywhere. PFCs — perfluorinated compounds — are found in household items like Teflon pans, microwave popcorn bags and pizza boxes, stain repellants, floor wax, carpet treatments and some shampoos.
PFCs don’t break down easily and they’re often found in the environment and wildlife, and dispersed into the air and water by industrial waste from some chemical plants.
They’re even in our bodies. In the United States and other developed countries, exposure to the chemicals is high — PFCs have been found in nearly 98 percent 2,000 Americans tested by the Centers for Disease Control and Prevention in 2004.
And yet, their full dangers are unknown.
Dr. B. Paige Lawrence, director of the toxicology training program at New York’s University of Rochester School of Medicine, says scientists need to get a grip on just how these chemicals affect the health of humans.
“Often when we think about pollutants and how they affect our health, we think about important and scary diseases like cancer,” ABC News quotes Dr. Lawrence as saying. “That’s very important, but as a society we often tend to overlook more subtle adverse effects, such as how a chemical affects our ability to fight infections.”
High PFC concentrations have been shown by previous studies to have adverse effects on the bloodstream and immune system of mice.
And in 2009, a study linked exposure to the chemicals to potential delays in getting pregnant for a group of more than 1,200 women.
New research from the Harvard School of Public Health suggests that exposure to PFCs, before and after birth may make childhood vaccines against tetanus and diphtheria less effective, lowering a child’s ability to respond correctly to the vaccine by making antibodies to fight those diseases later in life. This may make it such diseases to spread through the population.
Because previous research suggests people who eat lots of marine foods have higher exposure to PFCs, researchers did their study in the Faroe Islands, a small nation in the North Atlantic between Scotland and Iceland, looking at over 600 children and their mothers.
The researchers tested the levels of PFCs in the blood of the mothers when they were pregnant and in the children at age five and seven. The children’s immune system responses to vaccines for tetanus and diphtheria were also tested.
The study found a correlation between PFC levels and immune response: higher levels of PFCs in both mothers and children was associated with lower numbers of disease-fighting antibodies in the children.
Mothers who had twice the level of PFC in their blood than other mothers had children that formed fewer antibodies after getting the diphtheria vaccine at five years old, compared with the children of moms with less PFC blood levels—40 percent less, to be precise.
When the children themselves were tested in 2008, at seven years old, study authors found that children who had doubled PFC levels in their blood showed a nearly 50 percent reduction in their antibody levels — and were two to four times more likely to have an immune response considered too low to be clinically effective.
Messing with disease prevention
“We were kind of shocked when we saw those numbers,” study author Dr. Philippe Grandjean, Harvard School of Public Health’s adjunct professor of environmental health told Time Healthland. “This is the first study to say that by (exposing children to these chemicals); we are screwing up a major aspect of disease prevention in our society. I’ve been in the field for quite a while, and this is a very strong signal.”
Since PFCs are commonly found throughout the Faroe Islands’ environment, even in polar bears that live far from pollution sources, researchers surmised the marine diet of Faroese people may have influenced the levels of PFCs in the children in the study.
The study was published in the Jan. 24 issue of the Journal of the American Medical Association.
Study author Philippe Grandjean said very few chemicals are known to have such an effect on the body’s immune system.
“The PFCs make the immune system more sluggish, so that it doesn’t respond as vigorously against micro-organisms as it should,” Grandjean said. “If vaccinations don’t work, there may be an increased risk of epidemics.”
But most health experts agree that even a weakened vaccine can still be effective in fighting disease, because vaccines work by creating what is known as herd immunity by breaking chains of infection by making a significant number of persons in a community immune or less susceptible to the disease.
Speaking to ABC News, Dr. William Schaffner of Vanderbilt University points out that both PFCs and vaccines have been around for the past 40 years, but many of the immunization programs in the U.S. and other developed countries have successfully eradicated childhood diseases that were widespread in the world war years.
But University of Rochester toxicologist Dr. Lawrence says a vaccine’s reduced effectiveness may affect people differently.
“For some people, a 40 percent reduction in immune response might not matter at all. For others, it could matter tremendously,” Lawrence said. “What we can’t do is predict who will be most affected. We don’t have the ability to look at individuals and know who will get sick and who won’t.”
“Certainly, this study begs to have further testing done on PFCs so, if in fact, subsequent studies demonstrate an impact on the immune system, this product is at least taken out of use going forward,” Dr. Ari Brown, co-author of “Baby 411” and a developmental pediatrician in Austin, Texas tells ABC News.
What can you do if you want to reduce your PFC exposure?
Because the mechanism of how PFCs actually enter a child’s bloodstream is unclear, Dr. Grandjean says he can’t give advice with certainty since But he recommends people should avoid microwave popcorn, lubricants for skis and snowboards, and furniture, carpet, shoes, and clothes that treated with stain repellents.
“I don’t feel comfortable with the compounds for myself and my family and would rather eliminate them,” he told Reuters.
His comments have unleashed a bit of a storm in scientific circles.
Writing in her ScienceBlogs.com syndicated blog ERV, Abbie Smith points out: correlation does not equal causation.
“What (Dr.) Grandjean has is a very interesting observation,” she says, “but the biochemical and physiological ins-and-outs of that observation are still unknown.”
An outcome is a result of many factors, Smith points out. “Maybe there is some genetic quirk that has a negative effect on processing PFCs that also disturbs immune function. Maybe exposure to PFCs interferes with vaccine adjuvents,” she says, noting that the aluminum gels and aluminum salts used as Immunologic adjuvants have the same size range as PFCs.
“Maybe there is something else about eating more fish that is negatively effecting vaccine responses and PFCs are just a proxy measure that have no direct effect on the phenotype,” she says, noting that equating correlation with causation could be dangerous.
“An innocent correlation without causation, while the real culprit goes unrecognized,” Smith, a graduate student studying the molecular and biochemical evolution of HIV within patients and within populations, says.
Even many experts were not swayed.
Dr. Anthony Dayan, an independent toxicologist who has worked as an industry advisor, tells Reuters, “The study proves nothing” because it didn’t account for other considerations — like how compounds in oily fish called polyunsaturated fatty acids may also suppress the immune system.
The American Council on Science and Health’s medical director was more blunt.
“Absolute junk,” Dr. Gilbert Ross, told WebMD. No studies have found increased rates of tetanus or diphtheria among people with higher PFC concentrations in their bodies, he points out.
“It appears to represent this group’s attempt to link PFCs to some adverse health effect.” The study has “no clinical significance whatsoever,” he says.