The Great Influenza: The Epic Story of the Deadliest Plague in History

by John M. Barry

The Western world suffered the least, not because its medicine was so advanced but because urbanization had exposed its population to influenza viruses, so immune systems were not naked to it. In the United States, roughly 0.65 percent of the total population died, with roughly double that percentage of young adults killed. Of developed countries, Italy suffered the worst, losing approximately 1 percent of its total population. The Soviet Union may have suffered more, but few numbers are available for it. The virus simply ravaged the less developed world. In Mexico the most conservative estimate of the death toll was 2.3 percent of the entire population, and other reasonable estimates put the death toll over 4 percent. That means somewhere between 5 and 9 percent of all young adults died.