Prions spread by one misfolded protein causing the next one to misfold by contact, then the body replaces the original protein giving more protein stock to misfold . I think it happens in glial cells rather than neurons. The idea is that the spike proteins cause the original misfolds and start the prion cascade. I don't think just few spike protein molecules which have somehow come from the environment and made it through the blood brain barrier will be enough to start that cascade.
Prions spread by one misfolded protein causing the next one to misfold by contact, then the body replaces the original protein giving more protein stock to misfold . I think it happens in glial cells rather than neurons. The idea is that the spike proteins cause the original misfolds and start the prion cascade. I don't think just few spike protein molecules which have somehow come from the environment and made it through the blood brain barrier will be enough to start that cascade.