REDUCED CHILDHOOD VACCINE RESPONSES IN CHILDREN EXPOSED TO PCB FROM MATERNAL SEAFOOD DIET.

Abstract

ISEE-373 Introduction: Persistent pollutants, such as polychlorinated biphenyls (PCBs), may affect immune functions as shown in connection with environmental high exposures of children, in experimental models and wildlife. This study was undertaken to examine the effect of PCBs on the immune response to infant/childhood vaccines. We examined healthy Faroese children, whose mothers had been exposed to PCBs primarily from eating pilot whale blubber. Methods: Two cohorts of healthy Faroese children were investigated in regard to antibodies (Ab) to diphtheria toxoid (DT) and tetanus toxoid (TT). One cohort (n = 131) was examined at 18 months of age, i.e. 6 months after their third routine vaccination against DT and TT. The second cohort (n = 106) was examined about 2.5 years after their booster vaccination at five years of age. Exposure to PCB was evaluated by measuring PCB in maternal milk, maternal pregnancy serum and the child's serum at the time of Ab measurement. Results: A strong positive correlation was found between the PCB levels in mothers and their children. A negative correlation was found between PCB levels and Abs against DT and TT in all comparisons in both cohorts. The correlations was statistical significant for DT Abs at age 18 months and for TT Abs at age seven years and also significant overall. Conclusion: This study documents that PCB exposure that extends into normal environmental exposure levels may cause a negative effect on the ability of normal healthy children to produce antibodies to standard T-lymphocyte dependent antigens such as DT and TT. Furthermore, the data suggest that the maternal exposure level during pregnancy may influence antibody production even in 7-year-old children without additional postnatal exposure to PCBs.