Both Spanish Flu of 1917-1920 & covid 2019/2020 cause cytokine storms.
Interesting parallel between these 2 illnesses.
Cytokine storms = inflammation
Which is why an ANTI-inflammatory like hydroxychloroquine works
Also gotta say the timing of WW1 with Spanish flu is odd to say the least.
sauce
https://scribol.com/anthropology-and-history/history/spanish-flu-the-forgotten-pandemic-of-1917/
https://in.news.yahoo.com/explained-cytokine-storms-body-own-155238031.html