Author Affiliations: Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts (Dr Grandjean) (email@example.com); and Pediatric Clinic, Rigshospitalet-National University Hospital, Copenhagen, Denmark (Dr Heilmann).
In Reply: Human exposures to PFCs, the subject of our article, are a result of both past and current production. In our study, we measured children's exposure prenatally and up to age 5 years and found an association between elevated exposure to PFOS and PFOA and reduced clinically protective antibody levels to diphtheria and tetanus at age 7 years. While diphtheria may not be a serious risk in many western communities, we offered an additional booster vaccination to the 43 children (9%) not adequately protected against diphtheria or tetanus at age 7 years. The underlying question about the effect of environmental chemicals on the competency of the immune system is more likely to be reflected by specific vaccine responses than by total hospitalization rates for infectious diseases.1
Grandjean P, Heilmann C. Perfluorinated Compounds and Immunotoxicity in Children—Reply. JAMA. 2012;307(18):1910-1911. doi:10.1001/jama.2012.3633