A recipe for disaster

Some children have a neurological illness and are abnormal from the beginning," says Dr. Robert DeLong, a pediatric neurologist at Duke University. "But in standard garden-variety autism, they are pretty much normal for the first 12 or 15 months. Then they stop looking at you, stop talking and become more withdrawn. It's quite common and very real."

DeLong's research suggests that many cases of autism are genetically related to depression. Other scientists have linked autism to psychiatric disorders like obsessive-compulsive disorder and schizophrenia, or to birth defects caused by fetal exposure to chemicals. But when it comes to hard evidence of a MMR-autism link, the only published research is that of Andrew Wakefield, a British gastroenterologist.

Wakefield believes he has found the vaccine's smoking gun: fragments of measles virus in immune cells circulating in the blood of autistic children who suffer from severe gastrointestinal troubles. The live virus contained in the MMR vaccine damaged these children's guts, Wakefield maintains, then went on to damage their brains.

The families of the children Wakefield treats and examines suffer most terribly. Not only are they socially isolated and verbally stunted, many have chronic diarrhea or constipation or malnutrition. They frequently have multiple allergies, strengthening the hypothesis that they have had an overall immune system collapse.

A few other scientists are doing work related to Wakefield's line of inquiry, but most of the autistic and public health community aren't convinced. For a non-scientist it can be difficult to sort out the claims and counter-claims, but it takes a great leap of faith -- or a conspiracy theory -- to accept Wakefield's theories at face value.

For one thing, his theory maintains that it is the measles virus that causes the infection leading to autism. But if that were the case, says the Centers for Disease Control's Benjamin Schwartz, wild measles disease would be associated with autism, and it isn't.

Virtually all autism specialists have seen children with gastrointestinal problems, but they are a minority. And some believe the gastrointestinal problems of at least some of these children may arise from their peculiar behavior -- such as eating paint and other strange diets.

DeLong says that perhaps 3 percent of the several hundred autistic patients he's seen have had the chronic bowel problems.

Under pressure from Burton, the CDC and the National Institutes of Health have agreed to fund research that will help establish what percentage of autistics have GI or immune-system problems, and to look for biological markers that might set the group apart.

"Without a doubt a minority of autistics have this GI thing," says Belmonte. "But it wouldn't be any skin off anyone's nose to define a risk group and say this group should delay the vaccination for a year."

In the meantime, Burton has vowed to continue his investigations into the public health bureaucracy, which he claims imposes dangerous vaccines on our children by allowing physicians with conflicts of interest to oversee the approval process.

At a June hearing, Burton singled out the doctors who served on Food and Drug Administration and CDC panels examining American Home Product's Rotashield vaccine, which was introduced in 1998 but withdrawn a year later when a number of children suffered a kind of bowel obstruction called intussusception within days of taking the oral vaccine.

For Burton, Rotashield was the perfect example of a public health bureaucracy that ignored the interests of the public while furthering the profit motive of the pharmaceutical industry. "I was appalled to learn that at least six of the 10 individuals who participated in the working group for the rotavirus vaccine had financial ties to pharmaceutical companies developing rotavirus vaccines," he said at a June 15 hearing.

But the Rotashield recall could also be read, in a limited way, as a success story for the public health system's vaccine safety surveillance system.

Federal officials had detected a slightly higher than expected rate of intussusception during trials of the vaccine, and they kept an eye on it after the vaccine was introduced. When a year of post-market surveillance showed that 1 in 100,000 children receiving the vaccine had suffered the ailment, the FDA urged pediatricians to stop using the vaccine.

Further scrutiny of the data turned up a total of 100 cases of the painful, but usually treatable problem -- a total no more than twice the overall rate in the general population -- and the FDA recalled the vaccine altogether.

Since it's impossible for any vaccine to be tested on millions of people before it's introduced, it could be argued that the Rotashield experience is reassuring in terms of safety. Especially taking into account the fact that rotavirus, which the vaccine is designed to counter, hospitalizes 50,000 U.S. kids, and kills 40, each year.

Tell that to the parent of an autistic convinced that vaccines destroyed her child.

Frustration with the medical profession has led many to the cottages of alternative therapy, where autism is treated with vitamins, gluten-free diets and, most recently, a hormone called secretin. Some of the techniques seem to work for some children, at least a little.

But when it comes to potential conflict of interest, the alternative world is rife with it. Some of the leading advocates of the vaccine theory are involved in the promotion and sale of these therapies.

• View blog reactions