That flu shot you might have gotten recently faces a more complex challenge than scientists had formerly realized.
A strain of the influenza A virus perpetrated the "Spanish Flu" pandemic in 1918 that killed more than 20 million people. Related strains caused two other deadly global outbreaks in the 20th century, and virologists consider a future epidemic to be a perennial threat. All of that from a germ with a molecular toolkit of only 10 known proteins.
Systematic lab work and a dash of serendipity helped Jonathan W. Yewdell of the National Institute of Allergy and Infectious Diseases in Bethesda, Md., and his colleagues discover a new influenza protein. When the immunologists were investigating how the immune system recognizes virus-infected cells, they encountered the suspicious viral protein fragment, or peptide.