Well, as I’ve heard, the bird flu has already spread to humans (about 250), and it has killed 50% of them. Compare to the Spanish flu, which killed ~25% of those infected. On the one hand, you’d think it would mutate into a less deadly form so it could spread better, but on the other had one has to remember that the population is a lot higher these days and the virus doesn’t have to let you live very long before you can pass it on to many other people.
If you remember that, in a normal year, roughly 20% of all Americans catch some strain of flu (the real thing, not bad colds) at one time or another; any flu that kills more than the usual 0.5% to 1% of sufferers is cause for concern.
Some months ago I ran some fairly ‘rough & ready’ models of pandemic action with a high suscepibility rate (to account for more widespread travel) and a high mortality rate amongst the afflicted (60 deaths out of 117 cases, so far). The model predicted a billion deaths worldwide.
After a quick change of trousers, I tuned the model down until the morbidity hit 20% (the estimated worldwide infection rate of Spanish Flu) and used a 12.5% death-rate for suffers (also from Spanish Flu - worldwide MR estimated at 2.5% when 20% of world infected, do the math). This dropped the death toll to around 160 million, which is not too far off David Nabarro’s 150m figure (here).
So I guess: -
(A) We both used similar models (a variant of the SIR model - Serfling’s sucks).
(B) At the very least, Dr. Nabarro is anticipating that Bird Flu will not be much more deadly than Spanish Flu. Or if it is, much of this will be offset by better medicine.
Personally I hope the virus cripples itself trying to get a foothold in the human species, as CP pointed out, killing your host is a piss-awful survival strategy. Now, has anyone tried telling the virus that?