# 1763
Of all of the graphic representations of the H5N1 virus, none strikes home for me more than the one above; the one that shows how vulnerable the young are to a novel influenza virus.
Of the cases recorded, roughly 95% of all avian flu victims have been under the age of 50 and more than 70% have been under the age of 30.
For reasons not well understood, this virus has a predilection for the young. Half of all cases are under the age of 20.
Whether the young have more exposure to the virus, or are more susceptible, is unknown. Nor can we say with certainty that this trend would continue should the H5N1 virus become a pandemic, although the evidence right now suggests that it could.
In the 1918 Spanish Flu, young healthy adults suffered disproportionately from the illness, while those over 65 actually saw a lower than expected death rate. So there is precedent for a pandemic skewed towards the young and healthy.
It has been suggested that older people, having been exposed to more influenza viruses over the years, may pick up some cross-immunity along the way - even to what is assumed to be a novel influenza virus.
Additionally, the survival rates of those over the age of 30 have thus far been better than for those under that age, with 70% recovering. The survival rate for those under 30 is half that, running only about 35%.
Bottom line: At least for now, those under 30 are far more likely to contract the H5N1 virus than older people, and if they do, are twice as likely to die from it.
I'm sure we'll have a better handle on all of this for the pandemic-after-next. For now, all we can really say is that the young appear to be particularly at risk during an influenza pandemic.
Unknown, of course, are the eventual attack rate and CFR (Case Fatality Ratio) of any future pandemic. The trends we see today, among a small sampling of cases, may not hold true once a pandemic begins.
For planning purposes, the Federal government has elected to use the numbers from the 1918 Spanish Flu as a worst-case scenario. Basically an attack rate of 30% and a CFR of 2.5%.
Using these numbers, 90 million Americans could be stricken by the virus over the course of a pandemic, and roughly 2 million could die. Whether these numbers are realistic, or optimistic, won't be known until after the next pandemic is over.
Of course, these numbers are for the entire population. It is likely that the attack rate, and mortality rate, will be higher for those under the age of 30.
There are roughly 42 million kids between the age of 10 and 19 in the United States (2006 Est. US Census Data). Those under the age of 10 add another 40 million kids. Call it 82 million, give or take.
Now, assume that during the next pandemic 35% contract the flu. That's almost 29 million sick kids.
The hope is, the CFR will drop (well, frankly, it will have to plummet to help much), and so it is all but taboo to mention a death toll based on today's fatality rates. In years past, it was assumed any virus would have to give up lethality to become an efficient pandemic. Last year, the WHO indicated that wasn't necessarily so.
The following chart shows the number of fatalities among those under the age of 20, assuming a 35% attack rate, at various CFR's.
Of course, a 64% fatality rate is unthinkable.
As long as you ignore the fact that we are seeing roughly that rate among reported cases of avian flu right now.
A 2% CFR is quite bad enough, however. More than a half million dead kids. And the virus will have to lose more than 90% of its lethality to get us down to that number.
This virus likes kids, and young adults. Our emphasis must be on protecting the most vulnerable of our population.
That means closing schools early in a pandemic, and keeping them closed, for months if need be.
Kids can make up a lost year.
But only if they survive the pandemic.
I keep hearing `hedging' by local officials over when they would close schools during a pandemic. Some are very reluctant to do so, citing the hardships that would impose on working families, interruptions in education, and the loss of nutrition from the school lunch program.
All true, and all serious concerns. But none of them begin to compare to the tragedy of a million dead kids.
Any official who has any doubts in this matter needs to look at that chart again.
