The 1918 Influenza pandemic contained interesting properties which, to this day, still somewhat baffle the medical community. Most influenzas have a "U" shaped curve for mortality rates. However, the 1918 second wave in September contained a rather unusual "W" shape. In addition to affecting the very young and very old, the second wave of the 1918 flu pandemic also severely affected people between 25 and 35 years of age. One interesting theory for this phenomenon is that people over 35 years of age at the time had been exposed to a similar flu virus prior to 1889, granting them better immunity to the 1918 flu. Read more of this interesting analysis in the NIH article from 2006: 1918 Influenza: the Mother of All Pandemics
Disclaimer: This is an analysis of current COVID data from a data perspective only. I am not a doctor. This is not medical or legal advice. Consult your physician for concerns regarding COVID.
