The CDC has its work cut out for it this year as the swine flu vaccine ramps up for distribution in October. The fundamental problem they face is that most people have no real understanding of statistics. 

You can tell this, because the lottery still exists.  No one who understands statistics would waste their money on a lottery ticket, right? (Even worse are those people who only buy a lottery ticket when the stakes get really high. Your odds of winning the lottery are a lot lower for a $10 billion dollar prize compared to a $10,000 prize!)

As the New York Times points out, every day 2,400 pregnant women in America experience a miscarriage. At the same time, the CDC is strongly urging pregnant women to get the H1N1 swine flu vaccine (as they do for every flu vaccine), because pregnant women and their fetuses are at a much higher risk of complication from swine flu.  Therefore, you can reasonably predict that at least one woman will miscarry within 24 hours of receiving the flu vaccine.

Now we come to my favorite soap box: "correlation does not equal causation."  I want to get this printed on t-shirts and leaflets, and dropped onto cities. If you understand this principle, you will have a huge leg up on your fellow citizen.  

Let's say that your home loses power at the EXACT MOMENT that you pick up a pencil from the table.  People who don't understand that "correlation does not equal causation" will have tricked themselves into thinking that "picking up a pencil from the table causes the power to go out."  Picking up a pencil is CORRELATED with a power outage (at least that one time). But picking up a pencil clearly does not CAUSE a power outage.

The same is true for the flu vaccine.  A pregnant woman's miscarriage may be correlated (timed to coincide with) receiving the flu vaccine. But that does not mean that the flu vaccine caused her miscarriage. I'm not saying that there is no way that the flu vaccine can cause a miscarriage - I'm just saying that if ONE pregnant woman miscarries 24 hours after receiving the flu vaccine, out of all the pregnant women who receive the flu vaccine, then it's not likely that the vaccine is the culprit.

Unfortunately, between the 24 hour news cycle, and the fact that hysteria sells, I think we just have to accept that horror stories are going to be splashed everywhere as soon as the vaccination campaign begins.  The CDC is taking pains to make their process of information gathering transparent, and is doing their best to disseminate information and help allay public fears, but there's only so much they can do. 

This means that a lot of people who ought to get vaccinated won't, and swine flu will spread farther than it ought to, which puts everyone's health at risk. Personally, my plan is to get the flu shot, then spend the rest of the flu season washing my hands like a maniac!