"Anecdotal reports and uncontrolled studies have proposed that vaccines may cause particular allergic or autoimmune diseases," says Dr. Offit. "Such reports have led some parents to delay or withhold vaccinations for their children. This is very unfortunate, because the best available scientific evidence does not support the idea that vaccines cause chronic diseases. Scientific studies have shown, however, that reducing vaccination rates lead to increases in preventable infectious diseases."
In the article, co-authored by Charles J. Hackett, Ph.D., of the National Institutes of Allergy and Infectious Diseases, Dr. Offit critically analyzes proposed explanations for a link between vaccines and chronic diseases, such as the "hygiene hypothesis." The hygiene hypothesis states that improved hygiene and decreased early exposure to common childhood infections may actually raise a child's risk of developing allergies. Several studies support this hypothesis, says Dr. Offit, such as findings that children who attend childcare or live in large families are less likely to have allergies.
However, adds Dr. Offit, the hygiene hypothesis does not fit vaccine-related diseases. Vaccines do not prevent most common childhood infections, such as upper and lower respiratory tract infections, that form the basis of the hygiene hypothesis. On the other hand, vaccine-preventable inf
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Contact: Erin McDermott
McDermotte@email.chop.edu
215-590-7429
Children's Hospital of Philadelphia
3-Mar-2003