Dallas County's first mass distribution of the swine flu vaccine Wednesday tested the patience of thousands of adults and children, who stood outdoors for hours to snag a scarce shot.

But in the end, there was a lot of praise for how well the county dispensed the vaccine.

Despite chilly weather before dawn and intense sun by late morning, almost no one in the line complained about the long but orderly wait.

"This is pretty efficient," said Michael Buxton, a 53-year-old South Dallas resident whose breathing problems sent him in pursuit of the vaccine.

"I waited a couple hours, but it was a lot smoother than it should have been."

In all, the county inoculated about 3,600 adults and children, using up about a third of its supply of H1N1 vaccine reserved for uninsured, high-risk groups. They include pregnant women, people 6 months to 24 years old and those 25 to 64 years old with chronic illnesses.

Because of the shortage of the H1N1 vaccine, other mass immunization efforts around the country have been marred by angry outbursts from people who were turned away. Most clinics are enforcing fairly strict criteria for obtaining these flu shots.

"People were paying attention when we told them who could come here for shots," said Zachary Thompson, director of the county's Health and Human Services Department. "It felt like we were well prepared for this massive effort."

The free vaccinations will continue today and Friday at the health department's headquarters at 2377 N. Stemmons Freeway.

Only a dozen out-of-county residents were sent away Wednesday from the Dallas clinic, but they left peacefully, officials said.

Jack Hartley, a 79-year-old Mesquite man, also walked away willingly from a nurse processing his shot papers when asked to explain why he needed one. People 65 and older have been encouraged to forgo an H1N1 vaccination because many are immune to the new flu strain.

"I've had cancer off and on over the past 10 years," Hartley explained but added quickly, "I'm not here to get a shot. I just came with my neighbor for the ride."

The walk-in clinic attracted not only people who typically rely on the county's vaccine program, but a new cast of characters who find themselves uninsured during flu season for the first time.

"I'm 60 years old. I have asthma, and I'm uninsured," said Leslie Linton of Oak Cliff, when asked to explain why she waited in line for more than two hours. "If you must know, I lost my job at Citibank in 2007."

Francisca Sanchez, a 52-year-old Dallas woman, also was making her first visit to the health department.

"I lost my job as a machinist last summer," she said. "I am asthmatic, and I don't have insurance anymore."

With only a few early hiccups, the line of vaccine seekers steadily fed its way in and out of the building.

One of the glitches was parking. The massive lot was all but full at 7:45 a.m., and new arrivals had to be directed to side roads and other nearby lots.

It was unavoidable, Thompson said.

"Unless you had a big venue like the Cowboys Stadium, parking will always be an issue," he said. "We're working with it, and we're learning from it."

It also took longer than expected to process consent forms for each vaccine recipient. Some people required Spanish translators, slowing the process of determining which of three versions of the H1N1 vaccine to dispense.

"There's actual complexity in these vaccinations," said Dr. John Carlo, the county's medical director. "A preservative-free shot is for pregnant women. A nasal mist is for people 2 to 49 years old who don't have underlying health conditions. And a regular flu shot is for everybody else."

Another in-course correction involved a separate line for pregnant women, people in wheelchairs and those with other special needs. An hour or so after the clinic opened, county staffers were still setting up a separate entrance so those people would not have to wait for hours.

"There is no perfect scenario," Thompson said, "except making sure that there is enough vaccine so you don't need to hold mass vaccinations."

Garland's health department also reported an orderly process Wednesday. School district health officials had 1,000 doses on hand to distribute to pregnant women and children with underlying medical conditions.

By 3:40 p.m., officials had administered 220 doses.

"We rely on the school district because of the number of nurses they have vs. our small staff," said Richard Briley, the city's managing director of health.

Staff writers Jeffery Weiss, Ray Leszcynski and Jordan Hofeditz contributed to this story.

The Dallas County health department will continue offering the swine flu vaccine today for county residents who are low-income, uninsured and at highest risk of severe flu complications. Those risk categories include:

• Pregnant women

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

• Health care workers or emergency medical personnel

• People 6 months to 24 years old

• People 25 to 64 years old who have chronic medical conditions