When widespread public health emergencies like swine flu surface, it falls largely on three key people to take charge of the government's response: the secretary of Health and Human Services, the director of the Centers for Disease Control and Prevention and the commissioner of the Food and Drug Administration.
But nearly 100 days into the Obama administration, all three of those critical posts are vacant.
Visit ABC News' special section on swine flu to separate the facts from the myths, learn how to prevent the virus, and link to information from the Centers for Disease Control and Prevention and the World Health Organization.
Though Kansas Gov. Kathleen Sebelius is expected to be confirmed as secretary of Health and Human Services Tuesday, today HHS is the only department within the executive branch of government lacking a secretary.
And while some said holes at the highest levels of government are impeding the response to swine flu, others insisted the vacancies are not a problem.
"Philharmonics play without a conductor," a top federal health official told ABC News today. "There are a lot of people 'round who have been breathing this stuff for a long time."
Of 20 top spots at HHS, 19 are being filled by acting career and political employees, and the 20th position is empty.
"Our response is in no way hindered or hampered by not having a permanent secretary at HHS right now," White House press secretary Robert Gibbs said this afternoon.
Others, however, disagreed. This afternoon, former HHS Secretary Michael Leavitt called having top spots unfilled "a significant deterrent to our best reaction."
"I would say it's crucial that the new administration put a priority in getting HHS fully staffed," Leavitt said in a Monday teleconference. "The top 20 HHS officials are on vacation or being held by acting personnel. The secretary of HHS is the key player throughout the federal government in a pandemic or natural medical disaster. Some concentrated effort needs to be made to resolve that."
With 40 confirmed cases of swine flu in the United States and no vaccine available, federal officials are gathered today at an HHS command center, where health officials are using giant flat screens to track the disease. At the same time, CDC and FDA labs, also under the purview of HHS, are working to develop a "reference strain" of the virus that can be used for vaccine production, according to a top federal health official.
Meanwhile, Sebelius is not yet cleared to lead the department. Her nomination came late because she was Obama's second pick for the position; the president first picked former Sen. Tom Daschle, who later withdrew from consideration.
At the CDC, Dr. Richard Besser is temporarily at the helm until an official replacement for former director Julie Gerberding is selected. Today Besser was front and center telling Americans about precautions they can take to stop the spread of the virus, such as washing their hands, staying away from crowded places and staying home if they feel ill.
"What I want people to understand is that we're concerned," Besser told "Good Morning America" today. "People should be concerned. We'll tell you what we know when we know it."