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Vaccine effectiveness reduced by common toxin

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January 30, 2012|By Deborah Kotz

Vaccines, we’re told, aren’t 100 percent effective. That’s why some of us come down with the flu after getting a flu shot.

Now a new Harvard School of Public Health study suggests this may sometimes be due to exposure to certain environmental toxins. The researchers measured levels of perfluorinated compounds (PFCs) - found in food packaging, stain-resistant carpets, and nonstick pans - in nearly 600 children who lived in the Faroe Islands in the Norwegian Sea and found that those who had the highest levels of PFCs had a 50 percent lower reaction to tetanus and diphtheria vaccines, according to the study published in last Tuesday’s Journal of the American Medical Association.

“Previous studies have suggested that vaccine effectiveness may be reduced by other chemicals, like PCBs, but with PFCs we saw a much steeper effect, and this was surprising to us,’’ said study author Dr. Philippe Grandjean, an environmental health physician at Harvard.

Levels of PFCs found in the Faroe children (who consume high levels of seafood associated with increased PFC exposure), he added, are similar to those found in American children, but it’s not known whether the same effect occurs with other vaccinations.

There’s certainly no reason for parents to panic over the finding, said Dr. Rick Malley, an infectious disease expert at Children’s Hospital Boston who wasn’t involved with the research. “I would say it’s an elegant study and it’s provocative, but it’s just showing an association, not a cause and effect.’’