-Health officials have been terrible at predicting when and how much vaccine would be available. Only about 44 million doses have been shipped so far. Initially, officials said more than three times that would be out by now.
-At times vaccine shipments have been inexplicably lopsided. For example, smaller counties in Illinois and California have received the same amount delivered to counties with seven times as many people.
-Health officials have stressed that people most at risk for swine flu complications should go to the head of the line, but they haven't tried to make sure that actually happened.
-And despite pledges that they would be transparent about the vaccine program, some health officials have refused to disclose where all the doses are going, and they have held back on public service announcements telling people who should be coming in for shots. Also, many states were slow to establish Web sites that give vaccination locations.
To be fair, health officials say, the government deserves credit for a herculean effort to develop and distribute a safe and effective vaccine against a deadly virus that was first identified only seven months ago.
"You have a brand-new disease that gets identified in April. By October, you have a vaccine for it. By any standards, it's a miracle," said Dr. Diane Helentjaris, director of the Virginia Department of Health office handling swine flu response.
But complaints have been mounting, with lawmakers this week holding hearings in Washington and elsewhere, pressing for explanations.
"Calls are still coming in to me about, 'Why can't I get the vaccine?"' said Andrea Stillman, a Connecticut state senator speaking at a Wednesday hearing in Hartford.
She noted reports of uneven distribution within her state, and of places where vulnerable patients can't get the vaccine. "Obviously we're very frustrated in southeastern Connecticut," she said.
People are frustrated everywhere, said Sen. Susan Collins, R-Maine. At a hearing in Washington on Tuesday, she complained of "layers of misinformation and miscommunication."
Arthur Caplan, director of the University of Pennsylvania's Center for Bioethics, said health officials should have done more to make sure limited doses get to the people most at danger from the virus. And he said they should have been tougher on nurses and other health-care workers who are putting their patients at risk because they declined to get a shot.
"It is not working right at all," Caplan said.
In their defense, officials at the U.S. Centers for Disease Control and Prevention have said that the main issue is insufficient vaccine from manufacturers - something CDC can't control - and that health authorities are doing the best they can. Officials say all their predictions have been based on what manufacturers told them, and that every step of the way they've warned the public that the flu and the flu vaccine manufacturing process are hard to predict.
"A lot of this is a function of not having as much vaccine as we would like to have," said Dr. Anne Schuchat, who heads the agency's immunization section.
The new swine flu, also called 2009 H1N1, has not turned out to be the deadly global disaster that experts have long feared. But it has sickened an estimated 22 million Americans, hospitalized about 98,000 and killed 4,000. It has proved to be similar to seasonal flu but a much bigger threat to children and young adults.
There was no vaccine to protect against the new virus, so manufacturers had to create a new one. In July, a government health official estimated 120 million vaccine doses would be available by late October. Later, the government backed away from that estimate when manufacturers couldn't crank out vaccine so rapidly.
The CDC has been coordinating the vaccine campaign, but it is not fully in charge. As a matter of tradition and law, states have had more public health authority than the federal government. Each state health department has made decisions about which clinics, doctor's offices and other sites get vaccine from a federally contracted distributor.
"It's a little bit of a messy process and we expect it to be somewhat bumpy in the first few weeks," CDC Director Dr. Tom Frieden said in early October.
The bumps lasted more than a few weeks.
Health officials seem to have a poor idea of how many doses to expect. Two weeks ago, they predicted 8 million doses in the following seven days; it turned out to be 5 million - largely because a tropical storm nearly derailed some deliveries.
Blown delivery promises have had ripple effects at the state and local level. In Alaska, deliveries have lagged significantly, and other states report similar experiences. "We've learned to not put too much faith" in any extended vaccine supply estimates, said South Dakota Health Secretary Doneen Hollingsworth.
Demand has far exceeded supply in many places, and hundreds and even thousands people have waited hours in line. Many have been turned away when the vaccine ran out or the clinic hours ended.
One Delaware pediatrician, Dr. David Epstein, said patients were "banging on the door" for swine flu vaccine, and at some moments he felt like a United Nations relief worker in a refugee camp. "Everybody is desperate for it," said Epstein, who ordered 2,300 doses but had received only 300 as of last week.
Supply problems have forced states to make hard decisions about where to send the doses and which patients should get it.
Tennessee kicked off its campaign by targeting health-care workers, and many rejected the offer. Georgia emphasized getting initial doses to pediatricians and clinics that serve children.
Minnesota randomly sent vaccine to clinics across the state as it became available, and then let the providers decide which patients should get it first.
"We haven't tried to micromanage the administration of the vaccine," said Buddy Ferguson, a spokesman for the Minnesota Department of Health.
Authorities made few attempts to police the crowds to make sure priority groups - like pregnant women, young people and those with certain health problems - got vaccine first.
There were inequities, too.
According to Illinois newspaper reports, tiny Kendall County got enough doses to cover nearly 20 percent of its residents, while Will County - with nearly seven times as many people - got just enough for 2 percent.
In California, Santa Cruz County at one point got nearly 30,000 doses, while Santa Clara County - again, with nearly seven times as many people - got less than half as much, local media reported.
In New York, Buffalo schools wanted to start vaccine clinics but hadn't received a single dose. School officials there were irate to learn New York City schools had begun vaccinating hundreds of thousands of students.
"How could the city of Buffalo, which contains the second-largest school district in New York State, not have been designated by your office to receive a proportional share of vaccine supply?" Buffalo schools Associate Superintendent Will Keresztes wrote Nov. 5 to the state health department.
Some inequities were corrected as more vaccine became available. But suspicions that money or politics played a role in some places were fed by news two weeks ago that Wall Street giants Goldman Sachs and Citigroup received swine flu vaccine for some employees.
Also contributing to public mistrust are health officials themselves. CDC officials have stressed repeatedly that they are striving to be transparent. They have held frequent news conferences and given updates on vaccine availability and the disease's toll.
But the CDC has refused to release information about where all the publicly financed vaccine has been going. The agency punted the question to states, but some states have been tightlipped, too.
If swine flu had turned out to be deadlier, the delays and communication problems might have been catastrophic. Now, cases are declining across much of the country.
Indeed, health officials are now beginning to worry that demand for the vaccine may wane, just as vaccine is becoming more plentiful, just as states are perfecting Web sites that help people locate providers, just as new efforts are under way to encourage more health workers to get vaccinated.
Federal health officials say they expect to start running a public service campaign about the shots shortly.
Associated Press writers Carla K. Johnson in Chicago; Zinie Chen Sampson in Richmond, Va.; Kristin Hill in Nashville, Tenn.; Susan Haigh in Hartford, Conn.; Carolyn Thompson in Buffalo, N.Y.; Randall Chase in Dover, Del.; Wayne Ortman in Sioux Falls, S.D.; Rachel D'Oro in Anchorage, Alaska; and Steve Karnowski in Minneapolis contributed to this report.