Saw this Reuters article (via Consumerist) on a study that found that vaccinating preschoolers against influenza correlated with a 1/3 drop in emergency room visits of preschoolers with flu-like symptoms. The study leveraged data from the U.S. and Canada, who, at the time, had different public health policies about when children should receive the flu vaccine. It even seems like there was a halo effect, where older children got less sick; maybe not surprising considering what most parents have experienced with daycare facilities being inevitable places for transmission.
If you’re interested in all things influenza, be sure to check out the Flu Trends project at Google.org (Google’s philanthropy website); they’re actually looking at influenza related search terms regionally to compare them to actual health data, and they’re getting some interesting results.
And, on a closing note, a very NSFW (language) but passionate take on vaccines in general from Penn and Teller: