Common Chemicals Make Childhood Vaccines Less Effective, Study Says
New research finds that chemicals commonly found in non-stick cookware, microwave popcorn bags and other manufactured goods may make childhood vaccines less effective, perhaps making it easier for certain diseases to spread through the population.
A study published today in the Journal of the American Medical Association suggests that exposure to perfluorinated compounds, called PFCs, before and after birth may lower a child’s ability to make disease-fighting antibodies for tetanus and diphtheria later in life.
Researchers studied nearly 600 children and their mothers from the Faroe Islands, a small nation in the North Atlantic between Iceland and Scotland. The researchers tested the levels of PFCs in the blood of the mothers when they were pregnant and in the children at age 5 and 7. The researchers also measured the children’s immune system responses to vaccines for tetanus and diphtheria.
The study found that higher levels of PFCs in both mothers and children meant lower numbers of disease-fighting antibodies in the children. Mothers who had twice the level of PFC in their blood had children with a 40 percent decrease in the number of antibodies formed after getting the diphtheria vaccine. The 7-year-old children who had doubled PFC levels had nearly a 50 percent reduction in their antibody levels.
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.”
Experts say a weaker vaccine can still be effective in fighting disease. But Paige Lawrence, director of the toxicology training program at the University of Rochester School of Medicine, said 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.”
The study authors said the marine diet of Faroese people may have influenced the levels of PFCs in the children in the study, since the chemical is commonly found throughout the environment, even in polar bears that live far from pollution sources.
But exposure to the chemicals is also high in the United States. In 2004, the Centers for Disease Control and Prevention tested the blood of more than 2,000 Americans and found certain types of PFCs in nearly 98 percent of them.