A mysterious disease swept the world in the early 1920s that put people into catatonic states; stiff and immovable like human statues. It was called encephalitis lethargica and it affected over 5 million people worldwide, and then was almost forgotten.
Knowing what we know now, what do you suppose caused this?
Not a direct answer to your OP, but these two articles are perhaps relevant:
https://www.algora.com/Algora_blog/2020/02/06/spanish-flu-of-1918-was-really-a-bioterror-attack-on-humanity
https://rodneydodson000.medium.com/what-you-didnt-know-about-polio-26d20cba98e5