From the onset of the COVID-19 pandemic there have been countless comparisons to the 1918 influenza pandemic in terms of overall medical impact. Many of the comparisons addressed overall cases which, given the lack of a confirmatory lab test in 1918 and no meaningful case definitions for both pandemics, make such comparisons patently invalid. Overall mortality comparisons, although methodologically flawed as well, do offer a reasonably comparative outcome measure and offers a greater degree of validity. This measure is further enhanced when adjusted for population and average life years lost (see accompanying table for mortality comparisons presented 3 ways). The resulting value(s) can also be used to assess and better quantify the cumulative health impacts of our interventions and give a more objective base for our decision-making. A concluding observation is presented on the impact of a rapidly developed vaccine on a 1918 type event.

Source: Of lives and life years: 1918 influenza vs COVID-19