But I didn't discount the parents' claims: I knew these parents personally and respected their judgment. Many were doctors or research professionals themselves. The only thing that connected a lot of us was a common history of chronic infections, mainly ear infections, and consistent doses of antibiotics.

I decided to attend a conference on autism and learn more about the biological research.

Before I left I went through Connor's photo album. I did this soon after he was diagnosed, but perhaps I was too close to him and too ignorant of autism to recognize dramatic changes. This time, I saw it: Connor at 11 months, smiling for the camera, looking into his daddy's eyes, touching his mommy's hair. Connor on his first birthday, after his morning visit to the doctor's office and MMR vaccination, no longer looking at anyone, no longer smiling. And perhaps the most revealing picture: Connor walking on his toes, one of the most common behaviors in autism. Within a day he had changed.

The conference speakers presented the theory that autism was part of a spectrum of related immune disorders on the rise in children. The immune dysfunction in the body was triggered by reactions to multiple vaccines, either an ingredient in the vaccines themselves or the accumulated damage of multiple vaccines to the immune system. The body reacted by attacking its own cells, an "auto-immune" response, with reactions in the body ranging from mild allergies and behavioral changes to severe neurological damage such as autism and seizure disorders.

This evidence made a lot of sense to me because I was seeing these kids with my own eyes everyday -- friends of mine whose kids were prone to severe allergies, asthma, attention and learning problems, all with no family history. When I was growing up, there was always one kid in the classroom who was allergic to eggs, who had circles under his eyes and pale skin. I never saw an autistic kid at all. Now I look around and see sick kids everywhere.

Dr. Andy Wakefield's presentation was particularly compelling. A respected gastroenterologist at the Royal Free Hospital in London, he had been minding his own business studying inflammatory bowel disease and Crohn's disease when he encountered something very curious that he hadn't seen before. When he tested the growing number of autistic children who had come in with bowel problems, he noticed that their GI systems were damaged as if they'd been diseased for years.

Wakefield listened to parents about the late onset of symptoms, the similar stories of regression and the parents' belief that vaccine damage may have caused the problem. When he ran more tests on the children he found measles virus in their GI tracts, where it wasn't supposed to be. He published preliminary findings in a respected British medical journal, the Lancet, and immediately came under fire from colleagues in the U.S. and UK.

As I listened to the evidence Wakefield had gathered, I looked around at the other parents. There was no commonality among us -- we were of all races and ethnic backgrounds and geographically spread out. A few of us had a genetic history of autism or allergies but most of us didn't.

If you controlled for all of these factors, what common link was there? Controlling for genetics, allergy histories in families and environmental toxins from varied geography, there was only one candidate left that applied to all of us -- a mandated vaccine program. Industrialized countries like the U.S., the UK and Canada were experiencing this tremendous rise in autism and other neurological disorders. And these were the same countries where modern medicine flourished.

Interestingly, Japan didn't figure among the other countries' high increase, and had withdrawn the MMR in 1993 because of concerns about adverse reactions. I started to become uneasy.

"I'm going to ask everyone a question," said the conference host after Wakefield's talk. "How many of you here believe your children have been damaged by vaccines?"

Seventy-five percent of the attendees stood up and raised their hands. One woman a few rows behind me was crying, and I knew intuitively that her faith in the medical establishment had finally crumbled. Her suffering was genuine; she sobbed quietly. When I looked back, she was embarrassed, covering her face with her hand.

But I was moved by her anguish, her private suffering, and I relived for a moment my own struggles since Connor's diagnosis. The long nights of guilt I felt as a mother, constantly wondering what I had done wrong to give him autism; the long days of research to find a cure -- the doctors told me to put him in an institution, but I wasn't going to leave him; the countless doctor visits and tests Connor bravely endured without understanding why he was hurting or receiving little relief.

And finally -- unsurprisingly -- I was overwhelmed with rage. I felt it building within me and it was like nothing I'd experienced before. I knew very clearly at that moment that I had crossed over to the other side, that I was convinced my son was a cash cow for an industry that tested its products in production rather than the lab, motivated by $2 billion per year in profits, no different in its potential for corruption than any other industry.

There were no higher standards in medicine than in any other business -- the rule of caveat emptor applied to vaccines as surely as it applied to any other consumer product. I could not trust the FDA and the CDC to protect me from pharmaceutical companies that wanted to get their products to market with as little testing as possible and to promote the repeated use of their products in order to maintain their monopoly under the guise of the public good.

I don't have a medical degree, but I have learned how to be a thoughtful medical consumer. Connor's up for his mandated boosters next year. I know now that he can have a simple blood test of his antibody titers, which measures his antibodies and confirms that he has the protection he needs against disease. I had the blood test done and he's protected.

There's no medical exemption from these boosters in my state for "sufficient protection based on antibody titers," so I'll have to use a religious exemption instead. I've accepted that there is no binding contract between me and the agencies and companies that purport to protect my child. But my bond with Connor remains, my responsibility as his mother expanding to include advocacy -- even activism -- along with love.

Order "Mothers Who Think: Tales of Real-Life Parenthood" from the editors of Mothers Who Think.