China finds eight cases of a mutation of the H1N1 virus, fueling scientists' fears that the flu strain could morph into something more dangerous. The mutated virus does respond to drugs and can be prevented by vaccines, a health official says.

As Thanksgiving approaches, travelers with a touch (or more) of the flu are faced with a dilemma. Do they fly, turning the plane into what one flight attendant calls a "petri dish in the sky"? Or do they get slapped with stiff cancellation fees from the airlines? A recent survey suggests 51 percent of travelers will choose to fly the germ-infested skies.

Federal health officials revise the number of Americans who've likely died from swine flu, saying the figure is four times higher than originally thought. The Center for Disease Control now reports the virus has claimed more than 4,000 lives.

As H1N1 spreads across the nation, health officials are pleading with the public: If you are sick, stay home. But for millions of Americans with no paid sick leave, the choice isn't easy. Can they afford to stay home to nurse the swine flu? "A person has to eat," says waitress Kara Knoche, right.

Across the country, children, pregnant women and people with compromised immune systems are waiting in long lines for H1N1. Meanwhile, some prison inmates are jumping to the head of the line because they are considered high risk. Federal health officials say high-risk people should get the vaccine, no matter where they are. And that's got some people hopping mad.

The supply of H1N1 vaccine is millions short of what was expected by now, and some people have waited in line for hours to get it and gone away empty handed. Health and Human Services Secretary Kathleen Sebelius says, "I know it's frustrating" but that there will eventually be enough vaccine "for everyone."

As the H1N1 virus continues to target children at higher rates than those experienced by the general public, hundreds of schools across the country have closed their doors to combat the spread of so-called "swine flu." So far, more than 100 children have died after falling ill with H1N1.