Let’s hope that policymakers heed the perspectives offered by these two panelists. But even the swiftest and wisest measures may not be enough to head off an avian flu pandemic whose death toll, according to Laurie Garrett “would dwarf all but thermonuclear threats.” Garrett offers a précis of the incomprehensibly discouraging trends:

The H5N1 virus, which first emerged in rural China in 1996-97, results in a 100% mortality rate for domestic birds, and a 55% death rate in humans. The virus is most lethal to children and young adults—the healthiest among us. It might be, says Garrett, that “the human immune system finds the virus so deeply foreign that it responds in a manner that proves lethal to human beings.” The region over which human and bird cases exist has been expanding steadily, largely due to migratory aquatic birds forced into contact with domestic fowl because of habitat destruction. So far, transmission has been from birds to humans, but “we assume the virus will punch through and make the transition to bona fide human transmission.” And the flu is unbelievably contagious, continues Garrett. It’s “viable and transmissible on solid surfaces for six days-- orders of magnitude more contagious than smallpox.”

Scenarios spun out by public health experts and governments offer small comfort, making overconfident assumptions about early detection in remote areas and ample supplies of flu vaccine, she notes. And Tamiflu, which may mitigate avian flu’s effect, is no panacea. In the case of widespread outbreaks, no airlines will fly the vaccine out of Switzerland, Garrett says.

Respondent Mark Lipsitch says containment of this virus won’t work. Blocking transmission of the avian flu cannot rely on identifying infectious cases, since people can be infected for days, shedding the virus, before exhibiting symptoms. So quarantines, which reined in previous outbreaks of diseases like SARS, won’t suffice. And, says Lipsitch, a “pandemic isn’t over in a week but several years, so you can’t hole yourself up in a basement for three weeks,” because the virus will be back three months or a year later. The only chance Lipsitch sees lies not only in better vaccines but in improved technology for vaccine production, to create an adequate global supply. Governments must immediately insist that factories convert to flu vaccine production, as well as come up with realistic public health plans.