H1N1 - it's all in the structures

A new report published in Science lays out the structural basis (in the antigen hemagglutinin) for the marked similarity between the "Spanish Flu" H1N1 of 1918 and the "Swine Flu" H1N1 of 2009.  Most notably, the antibody response to the 1918 strain confers immunity to the 2009, and the structural basis of this is shown in the study.  Awesome!  (Subscription required to read the full text.)