That propylene glycol (PG) may protect users of the e-cigarette from airborne bacterial and viruses dates back to World War II. ‘Air Germicide’, a story in Time magazine Nov 16, 1942, reported the research of Dr. Oswald Hope Robertson at Chicago's BillingsHospital. He showed that half a part per million of PG in air could kill bacteria and viruses in that air within seconds. He found PG could protect mice from influenza virus, and that monkeys could well tolerate living in air containing PG. On the face of it, e-cigarette users might indeed be better off....actually confers immediate short term positive benefits, by reducing the risk of its users inhaling live viruses and bacteria from room air. This is mind-blowing enough, but could its possible benefits also protect others close by? Is the e-cigarette more than a tool for reducing harm? Is it also potentially a talisman to ward off infection?