Influenza is a fascinating virus. When it undergoes antigenic shift, as the novel H1N1 (“swine”) flu did, it efficiently evades most people’s immune systems. Non-novel flu strains are bad enough, but antigenically novel strains can have a ridiculously high attack rate. John Barry’s book, The Great Influenza, is a (usually*) terrific read, and describes very clearly what can happen when a novel influenza virus encounters a naive population. In the case of the 1918 pandemic, the circulating virus had not only a very high attack rate, but was also violently virulent, killing a large percentage of those infected (at least after the first wave).
So far, the new flu has had the attack rate, but not the virulence. That isn’t to say it’s the equivalent of the common cold; it’s not. Influenza is a potentially serious disease, so the more people it afflicts, the more (in raw numbers) will become seriously ill or die. Still, we’ve been lucky so far.
But our we lucky or good? So far, I vote for luck. Our luck is due mostly to the virus’s lack of virulence, not to medical or public health breakthroughs. The pandemic has not been contained. Influenza likes crowds, and military bases and summer camps are crowded. The Air Force is now reporting that a large number of cadets at their Academy have H1N1 flu, a number likely to grow larger. But at least it’s a containable environment, right? Military recruits have to follow orders, after all. During World War I, containment and control of the epidemic failed at least in part to military orders, or lack of them. In the frenzy to fight, our military and government allowed soldiers who were ill or at risk to travel the world, leading to events such as the Death Train from Camp Grant in Illinois, which, while en route to another camp in Georgia, spread the flu from town to town, and arrived at its destination with up to ten percent of it’s passengers dead or soon to be dead. But we’ve learned from our experiences, right?
[An academy spokesman] said it was nearly impossible to determine the source of the outbreak because some cadets had fanned out across the world for various Air Force-related programs.
We’ve been very lucky so far, in that H1N1 is not more virulent than other influenza viruses. This luck may or may not continue. If we continue a “business as usual” approach to containment, we will be lucky if all we have to deal with is some mild suffering and days lost at work. I don’t like to contemplate what will happen if our luck runs out. But someone had better.
*His style is more than occasionally repetitive; the book might have been a bit better if the editor had been a bit less merciful, but I still strongly recommend it.