Lydia Heine

“pandemics are lethal. Antigen shift guarantees that the new virus will infect huge numbers of people, but it does not guarantee that it will kill large numbers. The twentieth century saw three pandemics. The most recent new virus attacked in 1968, when the H3N2 “Hong Kong flu” spread worldwide with high morbidity but very low mortality—that is, it made many sick, but killed few. The “Asian flu,” an H2N2 virus, came in 1957; while nothing like 1918, this was still a violent pandemic. Then of course there”
― John M. Barry, The Great Influenza: The Epic Story of the Deadliest Plague in History

“H1N1 virus of 1918, the virus that created its own killing fields.”
― John M. Barry, The Great Influenza: The Epic Story of the Deadliest Plague in History

“new influenza virus emerges, it is highly competitive, even cannibalistic. It usually drives older types into extinction. This happens because infection stimulates the body’s immune system to generate all its defenses against all influenza viruses to which the body has ever been exposed. When older viruses attempt to infect someone, they cannot gain a foothold. They cease replicating. They die out. So, unlike practically every other known virus, only one type—one swarm or quasi species—of influenza virus dominates at any given time. This itself helps prepare the way for a new pandemic, since the more time passes, the fewer people’s immune systems will recognize other antigens.”
― John M. Barry, The Great Influenza: The Epic Story of the Deadliest Plague in History