Reduced vaccine effectiveness tied to PFC exposure
By Nancy Lamontagne
NIEHS grantee Philippe Grandjean, M.D., has shown that higher levels of exposure to perfluorinated compounds (PFCs) are associated with reduced immune response in children. The study is one of the first to link childhood exposure to PFCs with immune system deficiency and the results point to the importance of assessing the immunotoxic potential of PFCs. In addition, the immunotoxic effects of PFCs and other environmental contaminants might help explain vaccination failures that have puzzled scientists.
As described in their paper published in the Journal of the American Medical Association (JAMA), Grandjean and his colleagues studied the immunotoxic effects of PFCs by evaluating about 600 children from the Faroe Islands, located between Scotland and Iceland. The people of these islands frequently eat marine food, which exposes them to a wide variety of contaminants, including PFCs, which accumulate in the marine food chain. PFCs are highly persistent in the environment and are widely used in food packaging and textiles, because of their stain-resistance and water-repellant properties.
“We’ve worked with this community for 25 years and have been very successful in conducting population studies,” says Grandjean , an adjunct professor of environmental health at the Harvard School of Public Health in Boston. “We have a record of doing something that is useful to the community and also useful to science.”
The investigators assessed prenatal exposure by measuring PFCs in the mother’s serum during pregnancy and later checked for the compounds in samples from the children at age 5. They used the antibody response to childhood immunizations as an indication of how well a child’s immune system was functioning, taking measurements of antibody concentration just before the last booster shot at age 5 and again two years later. The children with elevated exposure to PFCs showed lower antibody responses to childhood immunizations.
“When the PFC exposure doubled, the child lost about half of the antibody concentration and the risk of not being protected, even after four vaccinations, increased by a factor of two to four at age 7,” says Grandjean, who is also head of environmental medicine research at the University of Southern Denmark, Odense.
The researchers will continue to examine immune system dysfunction associated with PFC exposure, including responses to infectious disease. There are problems with vaccine effectiveness around the world, and Grandjean says that immunotoxicity needs to be examined to ensure vaccinations are effective both on individual and population levels. He also says that the impact of environmental contaminants on the immune system could possibly play a role in noncommunicable diseases, such as cancer, and autoimmune diseases, such as type 1 diabetes.
Citation: Grandjean P, Andersen EW, Budtz-Jorgensen E, Nielsen F, Molbak K, Weihe P, Heilmann C. 2012. Serum vaccine antibody concentrations in children exposed to perfluorinated compounds. JAMA 307(4):391-397.
(Nancy Lamontagne is a science writer with MDB, Inc., a contractor for the NIEHS Division of Extramural Research and Training, Superfund Research Program, and Worker Education and Training Program.)