One hundred years ago, the Great Influenza of 1918-1919 killed between 50 and 100 million people, more people than any other previous pandemic in history. (The Black Death killed fewer people but a greater portion of the population.)*

In Asia, there have been occasional bouts of avian flu, which involve transmission from birds to humans. (Avian flu has yet to develop person-to-person transmission.) One strain of avian viruses had mortality rates of between 30 and 70%.**

Avian influenza is common in the bird population of Asia. **

In 2016, U.S. based airlines (as well as foreign airlines’ flights to and from the U.S.) carried well over 900 million passengers. That does not include regional carriers elsewhere in the world​ or ground-based transportation. (I recognize that this represents total, not discrete, passengers.)†

Each year, hundreds of millions of people in the United States use public transit.‡

Influenza has an incubation period of 1 to 4 days; individuals are contagious from 1 day before they show symptoms up to 5 to 7 days after they get sick. ⊗

The takeaway?

GET YOUR DAMN FLU SHOT.

And for God’s sake, if you’re sick, STAY HOME.

*Barry, John M. The Great Influenza, p. 4.
**Ibid., p. 451.
†Bureau of Transportation Statistics, https://www.bts.gov/newsroom/2017-traffic-data-us-airlines-and-foreign-airlines-us-flights, retrieved Jan. 16 2019.
‡Federal Transit Administration, 2016 National Transit Summary and Trends, p. 33. https://www.transit.dot.gov/sites/fta.dot.gov/files/docs/ntd/66011/2016-ntst.pdf, retrieved Jan. 16, 2019.
⊗Centers for Disease Control, https://www.cdc.gov/flu/professionals/acip/clinical.htm, retrieved Jan. 16, 2019.</font size=1>