1. https://prions.rip/prions-are-coming/

2. https://www.pnas.org/content/116/39/19727

3. https://www.frontiersin.org/articles/10.3389/fneur.2017.00092/full

= lower bound for onset and diagnosis (at earliest 161d x 4.3 / 365 * 12 23 months): 1yr 11months. So in late fall of 2022

Upper bound for estimation is much higher, could be years (4.5 - 7.4 yrs).

This is just a very crude back of the envelope estimation. Going from animal models to human time is very crude and may not work at all.