RAY SUAREZ: When Wayne Marasco and his team identified a few antibodies out of the billions of collected that could bind with 10 major flu strains, they were elated and mystified at the same time. Since flu viruses and the human antibodies they spark are all different, Marasco discovery seemed to defy logic.
DR. WAYNE MARASCO, Dana-Farber Cancer Institute: How is it that we would have an antibody that would be reactive to all these different types of influenza?
PAUL SOLMAN: Scientists know that human antibodies attach themselves to the individual shapes of the virus' proteins, especially the head of the H, or hem agglutinin. But since the head's shape varies from virus to virus, how could the antibodies Marasco found bind to off them? The team carefully studied every part of the virus, until the explanation became clear.
DR. WAYNE MARASCO: The antibodies did not bind to the globular head, where most of the immune system directs its energies, but these antibodies were uniquely targeted to the stem and, most importantly, to the machinery in the stem that allows the virus to actually penetrate the host cell.
RAY SUAREZ: And since the stem is one element of the virus that does not change:
DR. WAYNE MARASCO: ... the hope is that this region can be the target of a new vaccine, able to get durable, lifelong immunity, and not seasonal immunity, as we do right now.
JUDY WOODRUFF: That excerpt is part of a documentary about the H1N1 virus called "Anatomy of a Pandemic." It airs tonight on most PBS stations.