Yeah, that seems to be the older understanding. We've now got two studies pointing to the role of beta amyloid as being substantially tied to tangling either herpes virus particles specifically or potentially pathogens in the brain more generally.

Linked previously but I'll link again:

https://www.ncbi.nlm.nih.gov/pubmed/26836158 dated 22 Feb 2016

https://www.cell.com/neuron/fulltext/S0896-6273(18)30526-9 dated 11 Jul 2018

These seem to reference Alzheimer's only in passing or potentially in relation to the infectious theory, but they specifically speak to the action of Beta Amyloid.