SANTA CLARA Co. -- Santa Clara County's first public H1N1 flu vaccination clinic ran two hours longer than expected and ran out of vaccine for those in attendance because of the high number of children who showed up.

Thousands of people waited for hours in this line which stretched for blocks around the Santa Clara County Fairgrounds.

“We got here at 7:30, so that wasn't too bad,” said Mark Castanon, a San Jose resident. “I went up and talked to the first person, who got here at 3:30 a.m.”

Police were on hand to help with the large crowds as some people grew anxious and frustrated, unsure if they would get in and concerned about others cutting in line.

Heather Harris says the H1N1 flu virus has only added to the stress of becoming a new mother.

“I'm due in five days, so have to get the vaccine for me and the baby,” said Harris.”I'm sure the shot is going to hurt less than the contractions, so I'm sure I'm okay with it.”

The vaccine is still only being offered to those in the high-risk groups -- mainly pregnant women, children, and those with chronic health problems. It could be weeks before supply catches up with demand and healthy adults will have access to the vaccine.

“It may take several more weeks for them, but again they're statistically not the ones at the highest risk,” said Marty Fenstersheib, a Santa Clara County health officer. “So if they can stay healthy and wait it out, there will be vaccine later down the road.”

People were asked to fill out forms and check which high-risk group they're in, but public health officials know not everyone will be truthful.

“We're depending on the honesty of people, as long as they're educated and understand if they're healthy and don't need the vaccine, they may be taking away a vaccine for someone who is a much higher risk and may end up in the hospital,” said Feinstersheib.

The health department is planning to hold another vaccination clinic here for high-risk groups next Sunday. They say the state is sending out more vaccine so people should also check with their doctors.