In a short paper in the Journal of the Royal Society of Medicine in July, 2003, Madjid et al., note that influenza immunization significantly reduces the risk of recurrent myocardial infarction, sudden cardiac death, and stroke. They suggest that rather than the oft quoted figure of 20,000 deaths per year in the U.S., influenza should probably be credited with more like 90,000 deaths per year.
Madjid et al., go on to question whether influenza should be considered a bioweapon risk, particularly in light of the project (now completed) to sequence the 1918 flu strain. As I wrote last week, I think publishing the 1918 sequence is critical to scientific progress and that the risks are overstated. Still, the notion that flu accounts for many more annual deaths than is typically acknowledged is interesting.