i know several parents who have decided against vaccinating their newborns for a variety of reasons, and i've always looked at the decision with agnostic curiosity.

i understand the merits of both arguments. by their very nature, there is a risk with vaccines. but it's really only because most people give their children vaccines that it's reasonably safe to decide to not vaccinate your child. you reap the benefits of other people's risk taking. classic game-theory scenario.

but that's all theoretical. i don't have kids and i haven't had to make the tough call. i just get to sit back and cogitate on things like "The Not-So-Crackpot Autism Theory" that discusses that there may have been very real risks associated with vaccination:

"The F.D.A. team's conclusions were frightening. Vaccines added under Halsey's watch had tripled the dose of mercury that infants got in their first few months of life. As many as 30 million American children may have been exposed to mercury in excess of Environmental Protection Agency guidelines -- levels of mercury that, in theory, could have killed enough brain cells to scramble thinking or hex behavior.

"My first reaction was simply disbelief, which was the reaction of almost everybody involved in vaccines,'' Halsey says. ''In most vaccine containers, thimerosal is listed as a mercury derivative, a hundredth of a percent. And what I believed, and what everybody else believed, was that it was truly a trace, a biologically insignificant amount. My honest belief is that if the labels had had the mercury content in micrograms, this would have been uncovered years ago. But the fact is, no one did the calculation.""

that's 30 million potentially exposed children. stupifying. think the responsible parties are looking at the business end of a major lawsuit? perhaps not , due to collateral shielding from legislative efforts intended to protect smallpox and antrax vaccine makers:

The provision would require those who wish to sue former makers of thimerosal such as Eli Lilly to instead pursue their claims through a federal vaccine compensation program that caps damages at $250,000, Carl said. Medical research has not established a link between autism and Thimerosal, but many parents believe the ingredient may be to blame and are suing manufacturers.

''Ask a parent of an autistic child if $250,000 is going to take care of that child's needs for the rest of his life and you will probably hear that absolutely not,'' Carl said."