News Health & Medicine H1N1 virus lacks Spanish flu’s killer protein Molecule responsible for extent of 1918 pandemic is missing in today’s swine variant By Tina Hesman Saey June 15, 2010 at 11:22 am - More than 2 years ago Share this:Share Share via email (Opens in new window) Email Share on Facebook (Opens in new window) Facebook Share on Reddit (Opens in new window) Reddit Share on X (Opens in new window) X Print (Opens in new window) Print BOSTON — The H1N1 swine flu just doesn’t have what it takes to be a real killer, a new study of the 1918 Spanish flu suggests. Scientists have been studying the 1918 Spanish flu virus to find out what made it so deadly.