Just over a century ago, a virulent flu outbreak was wreaking havoc on the world.
We know it now as the 1918 influenza pandemic, and its tremors were felt far and wide. By the end of its spread, tens of millions were dead.
The field of public health has taken a giant leap from the days of 1918, when virology was still in its infancy. Today, information is instantaneous and vaccines are in widespread use.