Dr. Francis Collins told USA Today that he’s “guardedly optimistic” a universal flu vaccine would be made available within five years.

A few years ago, he said, such a vaccine seemed “completely out of reach.” The flu virus is always mutating, rendering a vaccine from the previous year’s strain obsolete. But recently scientists pinpointed parts of the virus that don’t change – so if a vaccine targets that portion of the virus it should target all strains, Collins said.

http://www.cbsnews.com/8301-504763_162-20084289-10391704.html