Witnesses: Margaret Hamburg, Assist. Sec. for Planning and Eval., HHS; Jeffrey Koplan, Dir., CDC; William Clark, Deputy Dir., Office of Emerg. Prepared., HHS; Donald Henderson, dir., Center for Civilian Biodefense Stud., Johns Hopkins Univ.; Richard Alcorta, for the Amer. College of Emerg. Physicians; John Bartlett, pres., Infectious Dis. Soc. of Amer.; Stephanie Bailey, for the Nat., Assoc. of County and City Health Officials; Jerome Hauer, dir., Mayor's Off. of Emerg. Mgmt., New York, NY; Michael Osterholm, for the Council of State and Territorial Epidem.; Amer. Soc. of Microbiol.; Michael Lord, exec. dir., Comm. Off. Assoc.; and Assoc. of State and Territorial Health Officials.