Worries about the spread of the virus mounted Thursday as the nation's swine flu caseload passed 100, and nearly 300 schools closed in communities across the country. Federal officials had to spend much of the day reassuring the public it's still safe to fly and ride public transportation after Vice President Joe Biden said he wouldn't recommend it to his family.
Clinics and hospital emergency rooms in New York, California and some other states are seeing a surge in patients with coughs and sneezes that might have been ignored before the outbreak.
Scientists were racing to prepare the key ingredient to make a vaccine against the never-before-seen flu strain — if it's ultimately needed. But it will take several months before the first pilot lots begin required human testing to ensure the vaccine is safe and effective. If all goes well, broader production could start in the fall.
"We think 600 million doses is achievable in a six-month time frame" from that fall start, Health and Human Services Assistant Secretary Craig Vanderwagen told lawmakers.