Summary

In Chapter 18, "Influenza: The King of Infectious Disease," Osterholm talks about the disease he considers the biggest threat to the world. Each year, seasonal flu kills anywhere from 3,000 to 49,000 people in the U.S. alone, and yet seems to register as little more than an annoyance on most people’s threat matrices. Influenza is hard to get a handle on, because there are so many strains of it. They are defined by the proteins hemagglutinin (HA) and neuraminidase (NA). There are 18 versions of HA and 11 of NA, which means almost 200 possible strains of flu that can infect humans. Other flu viruses exist that currently only infect animals, but since flu viruses come from birds and pigs, but are fairly easily able to mutate to infect humans as well. This is why new flu shots are produced every year, and are still sometimes ineffective...