Lead author Philippe Grandjean, adjunct professor of environmental health at Harvard School of Public Health, said perfluorinated compounds can be transferred to children prenatally and postnatally from exposure in the environment, can adversely affect vaccine response.
Grandjean and colleagues analyzed data on children recruited at birth at National Hospital in Torshavn, Faroe Islands, from 1999-2001.
A total of 587 participated in follow-up examinations. Children were tested for immune response to tetanus and diphtheria vaccinations at ages 5-7. Perfluorinated compounds were measured in maternal pregnancy serum and serum of children at age 5.
Perfluorinated compound exposure was associated with lower antibody responses to immunizations and an increased risk of antibody levels in children lower than those needed to provide long-term protection.
Antibody concentrations in serum are a good indicator of overall immune functions in children, Grandjean said.
The study, published in the Journal of the American Medical Association, found a two-fold greater concentration of three major perfluorinated compounds was associated with a 49 percent lower level of serum antibodies in children at age 7.
"We were surprised by the steep negative associations, which suggest that perfluorinated compounds may be more toxic to the immune system than current dioxin exposures," Grandjean said.