Washington, Oct 27: As the deadly H1N1 swine flu spread widely in 46 of 50 American states with some 1,000 confirmed deaths since April, the Obama administration geared up to meet the threat on a war footing amidst a vaccine shortage.

After President Barack Obama declared the H1N1 swine flu a national emergency Saturday, his top health official Monday assured Americans that the swine flu vaccine "is coming out the door as fast as it comes off the production line."

Appearing Monday morning on three network news shows, Health and Human Services Secretary Kathleen Sebelius acknowledged delays in getting the swine flu vaccine to Americans, but assured that eventually there will be enough supplies "for everyone."

"We were relying on the manufacturers to give us their numbers, and as soon as we got numbers we put them out to the public," Sebelius said on a morning network news programme. "It does appear now that those numbers were overly rosy."

"We do have a vaccine that works," she said, adding that there are now roughly 16.5 million doses of the vaccine, which, she conceded, is still millions of doses below what is needed and what had been predicted, CNN reported.

Obama's proclamation signed Friday night and announced Saturday will allow hospitals and doctors' offices to get legal waivers of federal rules so they can handle large numbers of sick people as the outbreak spreads.

"The 2009 H1N1 pandemic continues to evolve. The rates of illness continue to rise rapidly within many communities across the nation, and the potential exists for the pandemic to overburden health care resources in some localities," he said in a statement.

"Thus, in recognition of the continuing progression of the pandemic, and in further preparation as a nation, we are taking additional steps to facilitate our response."

"The H1N1 is moving rapidly, as expected. By the time regions or health-care systems recognize they are becoming overburdened, they need to implement disaster plans quickly," White House spokesman Reid Cherlin said Saturday.

Since the H1N1 flu pandemic began in April, millions of people in the US have been infected, at least 20,000 have been hospitalised and more than 1,000 have died, said Dr. Thomas Frieden, director of the Centres for Disease Control and Prevention (CDC).

The CDC said 16.1 million doses of H1N1, or swine flu, vaccine had been made by Friday -- 2 million more than two days earlier. About 11.3 million of those had been distributed throughout the US, Frieden said.

Public health departments across the country are quickly running out of H1N1 vaccine and don't know when the next batches will arrive, media reports said.

Priority groups for the vaccine include pregnant women, caregivers and household contacts of children younger than 6 months, people between the ages of 6 months and 24 years, and anyone ages 25 to 64 with existing health problems.

Health care and emergency medical services personnel in contact with high-risk patients, or patients with flu-like illness, are also on the list. (IANS)