From the Document: "While both the pandemic of 1918 and COVID-19 [coronavirus disease 2019] are respiratory diseases largely spread through the air by coughing or sneezing, the two pandemics are different in important ways. The H1N1 influenza strain of 1918 had a very short incubation period--just 1 to 2 days--whereas the coronavirus incubation can stretch up to 2 weeks, and its spread is facilitated by asymptomatic carriers. Moreover, the flu pandemic of a century ago would penetrate deep into a victim's lungs straightaway, and its virulence could trigger an overreaction by the immune system, filling the lungs with antibodies that caused acute respiratory distress. As a result, victims were overwhelmingly the young and healthy. This is the inverse of COVID-19's age profile, which targets those with weakened immune systems. Despite these differences, lessons from the deadly pandemic of 1918 bear heeding today."
Africa Center for Strategic Studies: https://africacenter.org/