President Obama has declared the swine flu outbreak a national emergency, allowing hospitals and local governments to speedily set up alternate sites for treatment and triage procedures if needed to handle any surge of patients, the White House said on Saturday.    The declaration came as thousands of people lined up in cities across the country to receive vaccinations, and as federal officials acknowledged that their ambitious vaccination program has gotten off to a slow start. Only 16 million doses of the vaccine were available now, and about 30 million were expected by the end of the month. Some states have requested 10 times the amount they have been allotted.

Flu activity — virtually all of it the swine flu — is now widespread in 46 states, a level that federal officials say equals the peak of a typical winter flu season. Millions of people in the United States have had swine flu, known as H1N1, either in the first wave in the spring or the current wave.

Although there has been no exact count, officials said the H1N1 virus has killed more than 1,000 Americans and hospitalized over 20,000. The emergency declaration, which Mr. Obama signed Friday night, has to do only with hospital treatment, not with the vaccine. Government officials emphasized that Mr. Obama’s declaration was largely an administrative move that did not signify any unanticipated worsening of the outbreak of the H1N1 flu nationwide. Nor, they said, did it have anything to do with the reports of vaccine shortages.

“This is not a response to any new developments,” said Reid Cherlin, a White House spokesman. “It’s an important tool in our kit going forward.”

Mr. Obama’s declaration was necessary to empower Kathleen Sebelius, the secretary of Health and Human Services, to issue waivers that allow hospitals in danger of being overwhelmed with swine flu patients to execute disaster operation plans that include transferring patients off-site to satellite facilities or other hospitals.

The department first declared a public health emergency in April; Ms. Sebelius renewed it on Tuesday. But the separate presidential declaration was required to waive federal laws put in place to protect patients’ privacy and to ensure that they are not discriminated against based on their source of payment for care, including Medicare, Medicaid and the states’ Children’s Health Insurance Program.

As a practical matter, officials said, the waiver could allow a hospital to set up a make-shift satellite facility for swine flu patients in a local armory or other suitably spacious location, or at another hospital, to segregate such cases for treatment. Under federal law, if the patients are sent off site without a waiver, the hospital could be refused reimbursement for care as a sanction.

A few hospitals, including some in Texas and Tennessee, have set up triage tents in their parking lots to screen patients with fever or other flu symptoms. A Health and Human Services official said no hospitals had requested a waiver. David Daigle of the Centers for Disease Control and Prevention said he had not heard of any hospital that has faced a surge of patients so large that it had to set up a triage area or a treatment unit off site.

In Chicago on Saturday, health officials began giving free vaccinations at six City College locations, and within hours hundreds of people were turned away because supplies had been exhausted. The city distributed 1,200 vaccines to each site, immunizing more than 7,000 people, said Tim Hadac, spokesman for the Chicago Department of Public Health. All but two of the sites ran out of the vaccine.

At Truman College on Chicago’s North Side, lines formed at 7 a.m., two hours before the doors opened. Mary Kate Merna, 28, a teacher who is nine months pregnant, arrived too late to get a vaccination. “I thought I’d be a priority being nine months pregnant,” she said. “You hear it’s a national emergency and it scares you.”

In Fairfax County, Va., officials had planned to have swine flu clinics at 10 different locations on Saturday. But the county did not receive the number of doses it requested, and was forced to offer the vaccinations only at the government building. People began lining up with camping gear the night before to get vaccinations.

Merni Fitzgerald, Fairfax’s public affairs director, said officials were aiming to administer 12,000 doses of the vaccine to those most at risk for serious complications from the H1N1 virus, mainly pregnant women and children 6 to 36 months.

But that did not stop some other high-risk patients. “I lied and told the doctors I was pregnant,” said Theresa Caffey of Centreville, who has multiple sclerosis and nurses her 11-week-old son, Joshua. “I’m religious. I don’t lie. But it’s not about me. It’s for my son. It’s safer for him if I have the antibodies.”

In a briefing on Friday, Dr. Thomas Frieden, the C.D.C. director, acknowledged problems with the vaccine production. “We share the frustration of people who have waited on line or called a number or checked a Web site and haven’t been able to find a place to get vaccinated,” he said.

Federal officials predicted last spring that as many as 120 million doses could be available by now, with nearly 200 million by year’s end. But production problems plagued some of the five companies contracted to make the vaccine. All use a technology involving growing the vaccine in fertilized chicken eggs; at most of them, the seed strain grew more slowly than expected.

The manufacturers are “working hard to get vaccine out as safely and rapidly as possible,” Dr. Frieden said. But since it is grown in eggs, “even if you yell at them, they don’t grow faster.”

Since last winter’s more isolated cases of swine flu, the expectation that the virus would return with a vengeance in this flu season had posed a test of the Obama administration’s preparedness. Officials are mindful that the previous administration’s failure to better prepare for and respond to Hurricane Katrina in 2005 left doubts that dogged President George W. Bush to the end of his term.

There is no overall shortage of seasonal flu vaccine — 85 million doses have shipped, and the season has not started. But there are temporary local shortages. The seasonal flu typically hospitalizes 200,000 and kills 36,000 nationwide each year. But over 90 percent of the deaths are among the elderly, while the swine flu mostly affects the young.

The Polk County Health Department has started scheduling H1N1 swine flu vaccination appointments for persons who fall into the high priority groups recommended by the Centers for Disease Control and Prevention (CDC).     “Vaccine is still arriving slowly, but there is enough supply available to begin vaccinating more high priority groups beyond our school vaccination program,” Dr. Daniel Haight, director of the Polk County Health Department, said in a news release. “We are concentrating our efforts on vaccinating those in the high-priority groups who do not have a health-care provider.”

Some of the high-priority groups have already gained access to the vaccine, including as pregnant women, EMS and health-care providers and some children. The remaining groups recommended by the Centers for Disease Control and Prevention are the focus of the next segment of the distribution plan.

These groups include:

People who live with or care for infants younger than 6 months old

Anyone from 6 months to 24 years of age

Anyone from 25 to 64 years old who have medical conditions that put them at higher risk for influenza related complications.

Many community doctors and clinics also are receiving vaccine supplies and patients are encouraged to first contact their doctor to ask for vaccine availability. Any primary care doctor can order H1N1 vaccine and easily obtain it for free, along with supplies needed to give it.

For those without access to a private doctor, an H1N1 flu vaccine phone appointment line has been created for people in the priority groups to register for a free vaccination. The caller will be scheduled at the nearest clinic that has the vaccine. Scheduling should not be done at the individual clinics but rather by calling the centralized scheduling phone number at 863-519-7510.

As vaccine supplies become more readily available, private physicians, pharmacies and public events will be held in the near future. In the meantime, people are encouraged to contact their primary care provider to discuss any questions they have about the vaccine and to determine if their provider has it available. Private providers can charge an administration fee covered by most forms of health insurance.

Planning for a weekend H1N1 vaccination event is under way for the convenience of people within the priority groups who have been unable to get a vaccination elsewhere during the week. More details will be released next week.