https://www.history.com/news/spanish-flu...W74AmBAbyk
"The horrific scale of the 1918 Spanish flu pandemic is hard to fathom. The virus infected 500 million people worldwide and killed an estimated 20 million to 50 million victims— that’s more than all of the soldiers and civilians killed during World War I combined.
While the global pandemic lasted for two years, the vast majority of deaths were packed into three especially cruel months in the fall of 1918. Historians now believe that the fatal severity of the Spanish flu’s “second wave” was caused by a mutated virus spread by wartime troop movements..."
"The horrific scale of the 1918 Spanish flu pandemic is hard to fathom. The virus infected 500 million people worldwide and killed an estimated 20 million to 50 million victims— that’s more than all of the soldiers and civilians killed during World War I combined.
While the global pandemic lasted for two years, the vast majority of deaths were packed into three especially cruel months in the fall of 1918. Historians now believe that the fatal severity of the Spanish flu’s “second wave” was caused by a mutated virus spread by wartime troop movements..."