Editorial use only Open air barber shop at the University of California, Berkeley, USA, during the Spanish Flu pandemic. Moving such services outside and wearing face masks was thought to help reduce the spread of infection. The 1918 Spanish influenza pandemic, which occurred in several waves between 1918 and 1920, infected one fifth of the world population and killed between 20 and 50 million, more than had been killed in the First World War. The second wave of the pandemic, from August 1918, was much deadlier than the first, with high mortality rates among young healthy adults.
