s of this writing , there have
been 169 laboratory-conﬁrmed human cases of H5N1 inﬂuenza – avian ﬂu–and 91 of those people have died. It is impossible to know whether this particular strain of ﬂu will mutate in such a way as to be easily transmissible between people and whether the virus will remain as lethal as it currently is. But if those things happen and a pandemic ensues, then, “in the best of circumstances,” the World Health Organization says, it would kill 2 million to 7.4 million people. In a worst-case scenario, more than 100 million would die, several times...