Vaccinations during childhood could be made less effective by exposure to chemicals commonly found in plastic containers and food packaging, Harvard researchers have claimed.
By Nick Collins, Science Correspondent
7:30AM GMT 25 Jan 2012
The man-made chemicals, known as PFCs, are found in a variety of everyday items including non-stick frying pans, waterproof clothing and fast food wrappers.
Previous studies have linked high levels of PFCs, which can last in the body for decades, to earlier menopause and reduced fertility among women.
Now a new study contains clues that high exposure to the chemicals in the womb or in early life could also limit the protection offered by vaccinations to children’s health.
Researchers from Harvard University studied data on 587 children from the Faroe Islands, measuring PFC levels in the blood of mothers and five-year-olds.
They also measured the children’s levels of antibodies after receiving tetanus and diphtheria vaccinations at the ages of five and seven.
The study showed that children with a twofold increase in levels of three major PFCs had a 49 per cent lower level of antibodies at the age of seven.
This does not necessarily mean the vaccine would be half as protective, but researchers said that in 43 cases – almost ten per cent – the antibody levels were low enough that the children would have “little or no protection” against the diseases.
They told the Telegraph that while some children had very low PFC concentrations, others had more than tenfold increases.
The research did not, however, prove that the PFC exposure had necessarily caused the lower number of antibodies, an essential component of the immune system.
Writing in the Journal of the American Medical Association, Harvard University researchers said: “These findings suggest a decreased effect of childhood vaccines and may reflect a more general immune system deficit.
“If the associations are causal, the clinical importance of our findings is therefore that PFC exposure may increase a child’s risk for not being protected against diphtheria and tetanus, despite a full schedule of vaccinations.”
Dr Philippe Grandjean, who led the study, said: “Routine childhood immunisations are a mainstay of modern disease prevention.
“The negative impact on childhood vaccinations from PFCs should be viewed as a potential threat to public health.”