8Feb20114:59am, ESTGeorge Marks / Retrofile via Getty ImagesWoman sneezing. United States, circa 1950s.A cure for the flu? Bless youBy David R Arnott, NBC NewsA universal flu vaccine has been successfully tested on humans with the disease for the first time, it was reported Monday.This kind of story poses something of a challenge for the photo editor. How to illustrate it in an interesting way? Here's my attempt.