ZeroCovidColin2) The 1918 flu was spread via close quarters on ships because of a war. That war ended and the virus stopped spreading as travel by boat between countries stopped happening. As I'm sure you've noticed, massive COVID outbreaks have happened on Cruise ships.
If influenza of 1918 was as infectious as COVID is now, we would've had to develop a better vaccine for it than we have. In addition, that better vaccine would've wiped the flu out in a way current vax/immunity can't with COVID.
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