1.   And anti-viral drugs such as Amantadine are not effective against type B flu strains.

2.   And not just because Tom Glavine was sick with a violent flu strain that had his system working in reverse.

3.   A totally new vaccine would be needed to protect against this flu strain, and flu vaccine production takes four to six months.

4.   But the system worked well enough to catch a new flu strain in May, a virus that CDC initially feared might be the next killer variety.

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

6.   Countless thousands of flu strains have existed throughout history, Skinner said.

7.   Finally, all three flu strains were growing well enough in the egg lots used by manufacturers.

8.   Flu strains are constantly changing.

9.   Flu vaccine fell into short supply this year when the four manufacturers licensed to make it had difficulties growing one of three flu strains.

10.   Flu strains that spread person-to-person are a far greater threat to public health than those that spread from animals to people.