Mark Honigsbaum is a medical historian and lecturer in journalism at the City University, London. A regular contributor to The Observer and The Lancet, he is the author of five books, including The Fever Trail: In Search of the Cure for Malaria (2002), Living With Enza: The Forgotten Story of Britain and the Great Flu Pandemic of 1918 (2009), and, most recently, The Pandemic Century: One Hundred Years of Panic, Hysteria, and Hubris (2019). (March 2020)
In 1918, almost everyone had been exposed to some type of influenza before, meaning most people could count on a degree of immunity. The result was that the Spanish flu infected only a third of the world’s population. By contrast, no one has any immunity to the new coronavirus—hence the estimates that as much as 80 percent of the world’s population could have been infected by the time the pandemic will have run its course. The greatest reason for concern, though, is that so far, SARS-CoV-2 appears to kill about 2 percent of confirmed cases. That is a very similar mortality rate to the Spanish flu.