Park Nicollet Clinic abruptly shut down its flu-shot hot line Monday after it was swamped with 120,000 calls in four hours from people trying to get the H1N1 vaccine, officials said.

The clinic, which had announced that it had 17,000 doses, was so unprepared for the outpouring that its entire phone system temporarily crashed under the weight of the calls.

It was yet another sign of growing anxiety as people await news of where and how to get the new vaccine.

As of Monday, 150 Minnesota clinics had received shipments of the H1N1 or swine flu vaccine, according to Kris Ehresmann, director of infectious disease control at the Minnesota Department of Health.

For now, clinics are giving the vaccine only to people at highest risk for the flu, such as pregnant women and young or frail children, and the vaccine is being distributed by lottery to clinics because it remains in short supply.

By the end of this week, Minnesota should have received a total of 300,000 doses, Ehresmann said. But that's less than half the amount needed just for the highest-risk patients (an estimated 718,000 doses).

Because of the shortage, many clinics are reluctant to publicize the fact that they have the vaccine, said Ehresmann. "They don't have enough vaccine [for everyone], so they're just calling in the patients that they have that are high risk." For the same reason, state officials are not announcing the names of clinics that have received the vaccine, allowing them to contact their own patients.

Park Nicollet, however, posted the news on its website and phone lines, which prompted news stories over the weekend that it was taking appointments for flu shots.

By Monday morning, its flu hot line was jammed, said Joan Sandstrom, the clinic's vice president of primary care and behavioral health.

Between 7 and 8 a.m., 60,000 calls couldn't get through, according to the phone tracking system. No one knows how many times callers pressed redial. But by 11 a.m., the number of calls had doubled to 120,000, and the line was shut down.

Only about 500 people got through, she said.

"They literally clogged up and shut down our lines for the entire Park Nicollet system," she said, including Methodist Hospital and all of the clinics. For a while, nobody could get through, she said, including people with other health problems.

Once the hot line was closed, Park Nicollet issued a news release asking patients to send e-mail requests for flu shot appointments to flushot@parknicollet.com.

Sandstrom noted that many calls were from people who didn't qualify as high-risk patients. In fact, some tried to slip into the flu-shot clinics over the weekend, but were turned away.

For now, Park Nicollet is accepting only pregnant women, children 6 months to age 4, and kids 5 to 18 with chronic conditions or weakened immune systems.

Elsewhere, some clinics have already run out of H1N1 vaccine, including Children's Hospitals and Clinics of Minnesota.

"We got a lot of calls when word got out that we had it, but we were clear that it was a small number of doses and had been allocated to extremely high-risk patients," said Brian Lucas, Children's Hospitals' spokesman.

He said the first thing people hear when they call is a message saying that Children's Hospitals doesn't have any H1N1 vaccine, and that it will contact patients when it does. "That weeds out some of it," he said.

The phones are still busy, he said, but mostly it's parents calling to ask questions about flu-like symptoms in their children.

Staff writer Josephine Marcotty contributed to this story. Maura Lerner • 612-673-7384