"On April 29, 2009, in response to the global spread of a new strain of influenza, the World Health Organization (WHO) raised its influenza ("flu") pandemic alert level to Phase 5, one level below declaring that a global influenza pandemic was underway. According to WHO, "the declaration of Phase 5 is a strong signal that a pandemic is imminent and that the time to finalize the organization, communication, and implementation of the planned mitigation measures is short. […] This report provides an overview of key actions taken and authorities invoked by WHO and the U.S. government. First, it discusses the WHO process to determine the phase of a threatened or emerging flu pandemic and touches on a number of related issues. The report then examines actions taken by the Departments of Homeland Security and Health and Human Services and provides information about appropriations and funding for pandemic flu activities. Finally, the report summarizes U.S. government pandemic flu planning documents and lists sources for additional information about the situation as it unfolds. This report will be continually updated to reflect unfolding events."
CRS Report for Congress, R40554