In today’s global economy, a deadly influenza outbreak in Asia is only a plane ride away from becoming a health crisis in the United States. Avian flu, which has spread from domestic fowl to humans and from Asia into Europe, is particularly threatening. The virus involved, H5N1, is now established in humans and is racking up a mortality rate of about 50%. The avian flu virus lacks just one important characteristic of a pandemic: It is not yet easily transmitted from person to person. But given its recent history and the speed at which it could spread if humans were able to easily infect each other, U.S. companies must start to consider what a flu pandemic would mean for their businesses.