Parents Wonder: Is It Safe To Vaccinate?

The story is ominously familiar to anyone interested in autism. A child who seems to be developing normally visits the doctor shortly after his 1st birthday to get the MMR (measles/mumps/rubella) vaccine. Pretty soon, the parents start to wonder about him. Why isn't he talking yet? Why is he so fussy? Why so detached and unresponsive? When the child is diagnosed as autistic, the question is inescapable: was it the vaccine? The notion that childhood vaccinations cause autism has recently sparked intense controversy. In Britain, nearly 700 families have banded together to sue pharmaceutical companies on behalf of their "vaccine damaged" children. And some new parents are refusing immunizations, opting instead for "disease parties," where their babies can contract natural infections. In the United States, concerns about vaccines and autism provoked a congressional hearing this spring where heartbroken parents shared their stories and suspicions. The fears are understandable, but so far there is little evidence to support them.

The current brouhaha started two years ago, when Dr. Andrew Wakefield of the Royal Free Hospital in London published a study of 12 autistic kids who also had persistent gastrointestinal problems. Wakefield speculated that the weakened measles virus used in the MMR vaccine had infected the children's intestines, disrupting the normal process by which nutrients are absorbed by the blood and brain, and harmful substances are denied entry. Wakefield's group found no direct evidence that a toxin had entered the kids' brains. And because the study didn't identify the size of the population the patients were culled from, it couldn't establish even a statistical link between vaccination, bowel disease and autism. Still, the study's 1998 appearance in The Lancet, a respected British medical journal, made headlines on both sides of the Atlantic.

It also inspired further research. In a study published last year, researchers led by Dr. Brent Taylor of the Royal Free Hospital reviewed autism rates in eight British health districts over a 13-year period to see if they had spiked following introduction of the MMR vaccine in 1988. They hadn't. And once MMR was available, kids who got the vaccine exhibited no more autism than those who didn't. "If such an association occurs," the researchers concluded, "it is so rare that it could not be identified in this large regional sample." An expert panel convened by Britain's Medical Research Council reached similar conclusions after reviewing all available evidence. No one pretends that all the evidence is in; the British and U.S. health agencies are now conducting larger studies to investigate the vaccine hypothesis. Still, experts are virtually unanimous in urging parents not to forgo vaccines in trying to protect their kids. Even if the measles virus did emerge as a risk factor for autism, vaccination would be our best hope of eradicating the disease. Autism aside, the measles virus can kill.