A response posted to Megan McArdle's blog, in response to this post:

Children are no more of a 'resevoir for infection' than adults. Adults get sick, so do kids.

Please check recent research to validate the 98% figure.

An enormous 'public health detriment' has been autism. Hannah Poling will be the first concession in many more. Vaccines are the 'WMD' of the health industry.

Whatever your opinion of me and my comments, you have a right to them. Try, however, to keep an open mind as this issue unfolds. I think we are all in for unpleasant surprises.

Posted by palmrita | March 24, 2008 10:44 AM

Ok. I have to respond to this with what will amount to a basic primer in Immunology. Please bear with me.

At birth, our immune system operates on the principal of a random number generator. You see, it produces all of these defensive cell types without any real knowledge of what is needed. It is untrained. Unexposed to the real world of pathogens. So it uses its ‘random number generator’ to create antibodies to random protein structures that may or may not invade host.

This is a recipe to get us all killed, but luckily as infants, our immune system is bolstered by something called Transferred Immunity. Basically some of our mother’s antibodies carry over from pregnancy explicitly to bolster our untrained immune system. Even better, breastfeeding bolsters our immune system by transferring some of our mother’s antibodies allowing us to better identify and deal with foreign threats. (Insert long tirade about the benefits of breastfeeding here).

So how do we gain immunity? Or rather, what is the process that produces Acquired Immunity? Natural Selection (Danger! Forbidden concept alert!). Remember the random number generator I mentioned above? Well it doesn’t work alone. Our immune system works not only randomly, but also as a catalytically induced Positive Feedback Loop. Exposure causes an increased antibody production response, and this ‘trains’ the immune system to better handle antigenic threats.

To put it another way, our Immune system relies on Natural Selection to train it for Acquired Immunity (I know, I know. Natural Selection is only a theory. Never mind that it underpins all modern biology. Anyway…). The random nature of Immunity becomes ‘weighted’ toward those things it has been exposed to and has successfully repressed. Natural Selection trains our immune response to be better respond to those challenges to which it has been previously exposed.

With all of this in mind, how to vaccines work? They jump-start this process. A denatured or attenuated invasive microorganism artificially introduced into our system will trigger a response to that antigen. The reason we don’t die due to this exposure is due to the fact that those microorganisms have been artificially damaged or killed prior to their introduction. In other words we are artificially inducing a natural process in a way that increases the odds of the subjects survivability at initial and subsequent exposures.

As to linking thermisol to autism there have been repeated studies undertaken to explicitly confirm this hypothesis. No linkage has yet to be demonstrated.

In conclusion, I am all for open mindedness. But there can be a terribly short path between an open mind and GIGO. I’m all for people finding out the utility of each individual vaccine allowing them to make an informed decision. But to decide to forgo all vaccines due to ‘research’ is the height of irresponsibility. Your decisions impact far more than you. You are significantly increasing the odds of your children having an untrained response to a potentially high morbidity infection, and allowing them to act as a vector to a significant population of people who may not have the ability to effectively resist the infection for a variety of reasons. Children are no more a ‘reservoir of infection’ than adults are. However, they do not have the acquired immune response of an adult either.

Failing to vaccinate your children significantly skews the odds against them. Personally it strikes me as an extraordinarily foolish thing with which to gamble.