What caused the 1918 pandemic to become significantly more deadly in its second wave was the war inadvertedly forcing healthy asymptomatic carriers to stay in p

What caused the 1918 pandemic to become significantly more deadly in its second wave was the war inadvertedly forcing healthy asymptomatic carriers to stay in place, instead of preferentially spread their strain of the virus, while sending symptomatic carriers of the virus to hospitals which acted as conduits for transmission: https://en.wikipedia.org/wiki/Spanish_flu#Transmission_and_mutation https://en.wikipedia.org/wiki/Spanish_flu#Transmission_and_m...