ST. LOUIS COUNTY — Thousands of St. Louis County residents lined up for flu shots Saturday, some queueing up as early as 5:30 a.m. and waiting hours — mostly with young, fidgety kids in tow — for the H1N1 vaccine.

"It's been a long morning," said Jara Tyson, who brought 8-month-old Raegan to Lindbergh High School early Saturday morning.

But after an initial nerve-racked morning rush, those who waited for the swine flu shots got them, and vaccination centers had vaccine to spare at the end of the day.

The county planned to administer 10,000 doses on Saturday at five high schools but only used 5,446 of those.

Residents were asked to arrive in the morning for line tickets and to come back later during a designated period to get the shot.

Like so many other parents, Tyson arrived early for a ticket and then returned later to stand in line again.

"That was long and arduous. There's a been a lot of waiting," she said. "But I guess the end result is worth it."

The county said it would give preference to five priority groups, including pregnant women, children ages 6 months to 4 years and caregivers of infants younger than 6 months, because H1N1 appears to be affecting the young. Half of the reported cases have been in those age 25 or younger, and nearly all the deaths have been in people 65 and younger.

Most of the people who came out Saturday were parents with young children, many of whom were concerned that the vaccination centers would run out.

"I got in line at 5:52, and there was a line of cars up the street," said Heidi Klco, of Kirkwood, with 2-year-old Jayna. "I knew there was a limited amount, and that was my main concern."

Julie Sandler stood in a parking lot waiting for a line ticket that would enable her to come back and get shots for her three sons at Maplewood-Richmond Heights High School.

"I was told you had to bring your kids," she said, rocking her 2-week old. "So now it's just me, sitting here with three boys."

But aside from some miscommunication and initial traffic confusion, the morning progressed smoothly, officials and many residents said.

"I was really impressed. It was very orderly," Klco said. "Some people are complaining about the wait for the vaccine. But they've only been working on it since April. I'm impressed we have a vaccine at all."

As of this weekend, 28.2 million doses had been distributed to states, including 1.4 million to Illinois and just over 440,000 to Missouri.

Given the small amounts, the county health department followed the Centers for Disease Control and Prevention's guidelines for limited supplies, giving preference to just the five priority groups.

But with vaccine left over, and 10,000 more doses available to doctors who request it, the county may allow other groups to get the vaccine in coming weeks.

Dr. Dolores Gunn, the county health director, said Saturday that the next public vaccinations will be available Dec. 5 at Hazelwood West High School, Ritenour High School, Rockwood Summit High School, Parkway Central High School and Kirkwood High School.

So far, there have been 1,800 reported cases of H1N1 flu in the county. But, Gunn said, "that's just the tip of the iceberg." The number of cases that have gone unreported probably put the total much higher.

Gunn advised the typical precautions: washing hands and covering up when coughing or sneezing. She also advised parents to make sure their children are fever-free before letting them go back to school.

"Prevention," she said, "is always the best answer."