JACKSONVILLE, Fla. -- A House panel sought answers to the shortage of the H1N1 vaccine Wednesday on Capitol Hill.

Committee members grilled federal health officials about whether the government could have done more to make sure plenty of vaccine is available.

"We could've invested more, and yes, we could continue to invest more in the advanced development of all of these new techniques and new vaccines," said Dr. Nicole Lurie, the Health and Human Services assistant secretary. "And I believe that we need to continue to do that."

Also Wednesday, California Rep. George Miller pushed for a quick hearing on his bill to get five days paid sick leave for hourly workers if they get the swine flu or a similar contagious illness.

The catch is their employer must tell them to stay home. The worker can't make that decision on his own or he won't get paid.

There are 50 million workers in America who don't have paid sick leave.

Meantime, Clay County vaccinated more of its elementary school students Wednesday. The vaccine clinic is voluntary and about 30 percent of the students are participating.

On Thursday, the shots will be given at Argyle, Charles E. Bennett, Ridgeview and Middleburg elementary schools. Next week, Nassau County schools will be vaccinating students with their parents' consent.

Children are being encouraged not to strive for perfect attendance this year.

"The decision was that in this time of very potentially unprecedented flu season, we do not want to encourage children to come to school if they're not feeling well," said Terry Wenig, the superintendent from Buckeye Union School District near Sacramento, Calif., telling students if they're sick to stay home.

They'll reinstate the prizes for perfect attendance next year.

Nassau County's Health department is the latest in the area to get the vaccination.

Workers at a clinic in Fernandina expected about 100 patients Wednesday night. They were focusing on children, pregnant women and health care workers.

"We're receiving shipments on weekly basis," one health official said. "As we receive more, we'll expand the list of people eligible for the vaccine."

Next week the flu mist vaccine will be administered in schools in the county.

For more information from the Florida Department of Health, including information about flu clinics for local counties, visit MyFluSafety.com, and for a county-by-county look at daily updates, go to County-By-County Flu Updates.