Looking back at 100 years of flu [timeline]
This year is the centenary of the Spanish influenza pandemic of 1918. However, it was only by 2010 that the industry had started universal flu vaccine trials, following the Swine flu pandemic in 2009. Explore the last hundred years of flu, as we mark the Spanish flu centenary, from the four major pandemics to the medical advances along the way, with this interactive timeline.