The worst influenza pandemic in history was the Spanish flu of 1918-1919. It infected an estimated 500 million people (about one-third of the world’s population) and killed an estimated 50 million—more than the death toll for World War I. Even today, the seasonal flu outbreaks remain deadly. Between 291,000 and 646,000 people worldwide die from seasonal influenza-related respiratory illnesses each year, according to the U.S. Centers for Disease Control and Prevention.
During the first half of the 20th century, people used a variety of measures to try and protect themselves from the flu. One of these was camphor extracted from Cinnamomum camphora, or camphor trees. People might wear a bag of camphor around their necks to ward off the virus, while nurses and doctors might inject it into an infected patient’s arms and legs with a hypodermic needle. Today, camphor is one of the active ingredients in Vicks VapoRub—though the Food and Drug Administration regulates it in smaller and safer amounts.
