I don't see how your comments about influenza at the end of WWI can be compared to the Covid-19 epidemic we now have. The only thing in common may be the absence of a vaccine. In 1918 we had no influenza vaccine. In 2020 we have no Covid-19 vaccine.
While a 50 year life expectancy 100 years ago is not incorrect, it hardly can be considered normal for 100 years ago. See
https://u.demog.berkeley.edu/~andrew/1918/figure2.html. Compare the 1914-15 numbers for men & women to the 1917-18 numbers. There was a world war going on. Also see the different values for men and women in 1917. The 1918 numbers reflect both war and influenza deaths in men, and influenza deaths in women. By 1921 these number had bounced up to at least 60 years.
The world-wide flu epidemic of 1918-19 caused most deaths among young otherwise healthy adults. Older people, were much less affected.
That may be a lot more on point. But why rely on only hope?
Year | Male life expectancy | Female life expectancy |
1914 | 52.0 | 56.8 |
1915 | 52.5 | 56.8 |
1916 | 49.6 | 54.3 |
1917 | 48.4 | 54.0 |
1918 | 36.6 | 42.2 |
1919 | 53.5 | 56.0 |
1920 | 53.6 | 54.6 |
1921 | 60.0 | 61.8 |