Avian flu poses a threat of pandemic influenza

Most infectious disease researchers believe that a pandemic of influenza-like the Spanish flu pandemic of 1918 and 1919 that killed 50 million people-is inevitable. But when? That fear has gained new urgency with the resurgence in Asia of avian influenza, more commonly known as bird flu. A new outbreak of this flu strain has appeared in ducks and chickens in Thailand, Viet Nam, Malaysia, and China and has been transmitted from poultry to humans in a limited number of cases. There have been some deaths. According to Julie Gerberding, MD, director of the Centers for Disease Control and Prevention (CDC), the outbreak is "a statistical time bomb ticking." Person-to-person transmission has not been documented, but the avian virus appears to be evolving rapidly; if, for example, the virus becomes infectious to pigs, which also harbor human flu viruses, an exchange of genetic material could occur and create a virus that spreads not only among pigs but humans, too.

Against that backdrop, it is good news that the US Department of Health and Human Services (HHS) last month released the first draft of a proposal for how this country will respond to the threat of an influenza pandemic. HHS has been working on the proposal, the "Pandemic Influenza Preparedness and Response Plan," since 1993. The draft focuses on five areas: development and production of vaccine; disease surveillance; stockpiling of medication; research; and public health preparations.

The HHS plan is ambitious, and potentially contentious, because it asks taxpayers to, first, pay for stockpiling expensive medications that may not be used for years and, second, accept harsh travel restrictions and quarantines when necessary. The Administration calls the proposals "a starting point for public discussion," and even those provisions that win general acceptance will take time and funding to put in place. As for vaccine development, Anthony Fauci, MD, director of the National Institute for Allergy and Infectious Diseases (NIAID), says that "a full court press" is under way to develop vaccines that are effective against multiple strains of influenza. So far, two manufacturers have begun to develop vaccines to protect against the avian strain of influenza. Safety studies of those vaccines are slated to begin this month at NIAID. Results should be available by spring 2005.