The Big Fear
Ask parents what scares them most about the shots, and you'll likely get one answer: autism. Many people believe that the increased number of vaccines -- children now get twice as many as they did in 1980 and can receive up to 20 injections by their first birthday -- are to blame for the rise in kids with autism spectrum disorders (ASD). The idea first made headlines in 1998, when Andrew Wakefield, M.D., a British gastroenterologist, published a study of 12 children in The Lancet that linked the measles, mumps, and rubella (MMR) combination vaccine with intestinal problems that he believed led to autism. The following year, the AAP issued a warning about thimerosal, the mercury-containing preservative that was found in most vaccines. Though it didn't mention autism specifically, it suggested that the use of vaccines with thimerosal could theoretically push an infant's total exposure of mercury, a neurotoxin, above safe limits, and it recommended that the preservative be removed from shots. The vaccine-autism hypothesis was solidly in the mainstream by the time actress Jenny McCarthy went public with her belief that vaccines caused her son's autism, describing in heartbreaking detail how "the soul left his eyes" on a 2007 segment of the The Oprah Show. "It was enough to scare any mother," says Eileen Pike, of West Palm Beach, Florida, who has chosen to delay certain vaccines for her son, now 23 months.
However, at least seven large studies in major medical journals have now found no association between the MMR vaccine and ASD -- and this February, The Lancet officially retracted Dr. Wakefield's original paper. (Revelations that he had failed to disclose connections to lawyers involved in vaccine litigation also emerged.) In March, the U.S. Court of Federal Claims, Office of Special Masters, a group of judges appointed to handle cases of families who believe immunizations were responsible for their child's autism, ruled that thimerosal in vaccines does not increase the risk of the disorder. (In 2008, a federal judge did award compensation to the family of Hannah Poling, a child with mitochondrial disorder, a rare condition that can show symptoms of autism, which she was diagnosed with shortly after receiving five vaccines.) Several demographic analyses have also found that autism rates continued to rise even after thimerosal was removed from all vaccines except some flu shots.
So why are there so many stories of children developing autism shortly after immunizations -- not just in the media, but also in the Vaccine Adverse Event Reporting System, the federally cosponsored program that collects reports of suspected vaccine-related injury or illness? Experts believe that the association is almost certainly coincidental. Children get their first dose of the MMR vaccine at 12 to 15 months, the age at which autism symptoms typically become noticeable, says Paul Offit, M.D., director of the vaccine education center at Children's Hospital of Philadelphia and the author of Autism's False Profits: Bad Science, Risky Medicine, and the Search for a Cure. "It's the same reason why there are reports of SIDS deaths after DTaP (diphtheria, tetanus, and pertussis) immunizations," says Dr. Offit. "Infants start the DTaP vaccine between 2 and 6 months, which is the time they're also most likely to die from SIDS." In fact, some autism activists now believe that we should't even do more studies about a possible vaccine connection because they take attention and money away from important research that is investigating other potential causes of the disorder. "We have to move forward and be willing to accept what science tells us: Vaccines do not cause autism," says Alison Singer, president of the Autism Science Foundation and the mother of a child with autism.