Waterford - Mary and John DiFederico have been trying for weeks to get a regular, old-fashioned seasonal flu shot - the one they get every year, not the newfangled H1N1 vaccine - by calling their doctor, town senior center, Walgreen's and other retail chains that had offered vaccinations this year.

"I called a lot of places and nobody had any," Mary DiFederico said.

Her husband added: "I've never had this much trouble in all my life getting a flu shot."

A little after 4 p.m. Wednesday, the Waterford couple's search finally ended successfully at the offices of the VNA of Southeastern Connecticut when their turn came for vaccinations.

The DiFedericos were among hundreds of people, mostly senior citizens, who came to the VNA's seasonal flu shot clinic Wednesday, the first the public health agency has been able to offer in weeks because of limited supplies of seasonal vaccine. Thirty vaccination clinics it had planned to run at senior centers and other venues had to be canceled after vaccine it ordered never arrived, said Leah Hendriks, supervisor of school health and immunization for the VNA.

Mary Lenzini, VNA president, said the 400 doses offered at the clinic Wednesday arrived after the first shipments, which were used mainly to inoculate home-bound VNA patients, and is all the VNA expects to get this season.

Lenzini put out word of the clinic selectively through senior centers and doctors' offices, not wanting to broadcast it widely because, with only 400 doses, she didn't want to end up having to turn a lot of people away.

The shots offered Wednesday were available only to four groups: those 50 and older, those with chronic conditions such as asthma and diabetes, pregnant women and those who live with or care for infants.

For some, the experience of trying to follow their doctor's and public health officials' advice to get a flu shot was not only an exercise in frustration, but also one that left them scornful of the vaccine production and distribution system.

"The greatest country in the world can't seem to get flu shots for its seniors," Don Bowers of Niantic said, shaking his head. He had come to the VNA clinic with his wife, Dorothy, after weeks of searching.

This year's seasonal flu season isn't expected to peak until the first months of next year, so those who get flu shots now will be protected. Typically, seasonal vaccines are given around this time, but the Centers for Disease Control had been advising the public to get seasonal shots earlier this year, before the other flu virus, H1N1, began circulating widely.

But for many, that advice proved hard to follow.

Tom Skinner, spokesman for the CDC, said thus far this season, about 94 million doses have been distributed nationwide - 10 to 15 million more than last year - and that demand this year has been unusually high. All the attention given to H1N1, also called swine flu, caused more people to become concerned about the flu in general and take steps to prevent it. The dozens of clinics offered this year at retail outlets made getting a seasonal flu vaccine easier than ever for some.

But for those uncomfortable or unable to wait in line at Walmart or CVS for a shot, or who preferred to wait and get it from a familiar source like their doctor or senior center clinic, were out of luck.

"I did try to go to the CVS to get it, but they had run out, and I wasn't too keen on getting it there, anyway," said Doris Beebe of East Lyme after receiving her flu shot at the VNA clinic.

Another who had tried unsuccessfully to get a shot at CVS, Geraldine Sincali of Quaker Hill, heard about Wednesday's clinic from her doctor.

"At CVS, the line was too long," she said.

After that, Sincali was hoping to get a shot during an upcoming doctor's appointment, only to find out he had no vaccine.

At Lawrence & Memorial Hospital in New London, Warren Rogers, director of pharmacy, said he finds fault with a system that has allowed retail stores to get vaccine before health care providers, and has written to Attorney General Richard Blumenthal with his concerns. The hospital got about 60 percent of the seasonal vaccine it had ordered for its patients, staff and affiliate sites.

"The Targets and CVSs and Walgreens pulled a lot of vaccine out of the system," Rogers said.

According to information on the CDC's Web site, 114 million to 115 million doses of seasonal flu were originally expected to be produced. Skinner said vaccine companies had trouble meeting demand in part because much of their vaccine capacity was taken up producing H1N1 vaccine instead of the seasonal variety.

Skinner said most of what has been produced has already been distributed, although "there is some still making its way out into the pipeline."

The production and distribution system, he said, is run entirely by private companies, and as such, there is little the CDC can do if companies send it to large retail chains ahead of individual doctors' offices or public health agencies. In addition, the amount of vaccine companies decide to produce each year is a "guessing game" of trying to predict demand, and companies tend to underestimate rather than risk ending up with surpluses.

"It's very much a system in the private sector, and it's not a perfect system, and it leads to spot shortages," he said.

The seasonal vaccine produced for this year will be effective protection against one of the main strains expected to be circulating, he said, but not a second, called H3N3, that's turning up in other parts of the world.

"We're keeping an eye on that one," he said. "It's not in the seasonal vaccine."

Both Skinner and Dr. Norman Edelman, chief medical officer for the American Lung Association, said problems in the country's production and distribution system highlighted by this year's experience need to be addressed.

"We've got to come up with a better way to make vaccine quicker," Skinner said. The current system, in use for the past 50 years, relies on eggs as the base medium for producing the vaccine.

"It's safe and effective, but it's resource-intensive," he said.

Dr. Edelman said problems must be tackled with federal government incentives and other investment.

"The American Lung Association has long criticized the lack of investment into modernizing the way flu vaccine is made," Dr. Edelman said. "The society and the medical community are putting a lot of pressure on Congress about this, and they should be sensitive to this issue."

Expecting no more seasonal vaccine, physicians like Dr. Steven Powell of Norwich is left telling his patients still looking for flu shots that he's hoping for a mild seasonal flu season this year, and that if they got a shot last year, they'll still have some immunity. A specialist in pulmonary and critical care medicine, he ordered 1,000 doses, and received only 500.

He does hope to see the distribution system changed, so that health care providers will get preference over retail chains, who give shots strictly on a first-come, first-served basis rather than according to age and medical risk.

"It probably is better to distribute it through health care professionals," he said. "They have better built-in triage methods."

j.benson@theday.com