your question: higher levels of beta amyloid would correlate with lower levels of virus. A metaphor for answering it: if the protection arrives late and the har

your question: higher levels of beta amyloid would correlate with lower levels of virus. A metaphor for answering it: if the protection arrives late and the harm is done then the number of protectors can't be used to predict the harm. So to anaylize the correlation one has to know if the effect of the protection happen before it makes the harm or not. That is the speed here is an essential ingredient. Emperator caveat: I applied abstract reasoning and a metaphor, don't know about the specific details of how beta amyloid is generated.