Swine Flu vaccine may be delayed

(NBC) - Manufacturers making swine flu vaccine have hit some snags, but U.S. health officials say they're not worried. They fully expect to have enough vaccine this fall for those who need it most.

Clinical trials are set to start in just a few weeks to make sure the vaccine is safe before offering shots, but production isn't going as smoothly as expected.

Baxter pharmaceuticals - the only American manufacturer producing swine flu vaccine - has products ready to go, but they're made from cell cultures, and that's not FDA approved.

For the U.S., vaccines must be grown in eggs.

Another company - Novartis - reports its eggs are yielding less than half the active ingredient they need.

"Right now we need the virus strain to catch up," Health and Human Services Secretary Kathleen Sebelius said.

Health officials insist that'll have no impact on delivering the first doses.

"We still feel we're on track for a vaccine by mid-October," Sebelius said.

The CDC fears once students head back to school, the H1N1 virus could begin to spread quickly. Unlike the regular flu, this virus is taking its toll on young people. So educators are getting ready for what could be a mass immunization campaign in schools.

"The children obviously have tremendously high risk, we want schools to be centers of the community anyway, and so if schools can be part of the solution we absolutely want to do that," Secretary of Education Arne Duncan said.

Pregnant women are also at risk, and the CDC says they should plan on getting shots.

This week, the government set aside more than $800 million to stock up on vaccine ingredients, and President Obama has designated $1.8 billion in emergency funds just to get ready for what he's said could be a "looming" threat.

Since most of the vaccines are being made overseas, there's concern those countries might get the first doses before the U.S. The  CDC said Friday, based on their contracts with manufacturers, they're confident the U.S. will get enough vaccine to start immunizing students mid-fall.