Since 1997, avian flu strains have killed millions of birds in nearly a dozen countries.

That flu strain, named for where it originated, is one of the more dangerous strains.

They believe this could even eventually lead to a "one-injection for life" against all flu strains.

I was afraid of all the flu strains and all the stuff kids pass around to each other, then bring home.

Since 1997, avian flu strains seem to have infected thousands of birds in 11 countries.

The mid-1970s were important for the evolution of flu strains.

I urge my kids to get it too, because you never know how nasty this year's flu strain might be.

The protection lasts only eight to 10 months, and the flu strains change from year to year.

What flu strain is going to be the next pandemic and when?

But, they say, it may lead to information allowing scientists to predict which emerging flu strains are especially dangerous.