Press secretary Robert Gibbs today said that the continuing vacancies at the Department of Health and Human Services have not in any way impacted the administration's response to the swine flu outbreak.

Gibbs this afternoon repeated that President Obama is getting regular briefings on the crisis, and explained that Homeland Security Secretary Janet Napolitano has taken a lead role because of a presidential directive that "denotes that interagency coordination" be handled by DHS.

"Our response is in no way hindered or hampered by not having a permanent secretary at HHS," he said when asked about Kathleen Sebelius' still-pending confirmation. "There are professional staff over there as we speak helping to coordinate this. ... Having said that, we're certainly hopeful that Secretary - soon to be Secretary Sebelius will be joining them without delay tomorrow."

The SEIU is using the crisis to rally support for Sebelius' nomination, criticizing Republicans who have held up a final vote.

Earlier today, Obama himself said that the crisis is "obviously a cause for concern and requires a heightened state of alert. But it's not a cause for alarm." Speaking at the National Academy of Sciences, he promised regular updates from various government agencies "so that they know what steps are being taken and what steps they may need to take."

"One thing is clear -- our capacity to deal with a public health challenge of this sort rests heavily on the work of our scientific and medical community. And this is one more example of why we can't allow our nation to fall behind," he said, pivoting to planned remarks promoting further efforts in support of the sciences that his administration is making.