I think My69z was partially correct when mentioning CD4+ counts during the switch from CCR5 to CXCR4 tropism as the dominant viral strain. I think the depletion of CD4+ of course accelerates the HIV infection/replication cascade into AIDS.

Here's an article that goes into more depth. Sorry if I'm reposting something already talked about.

https://journals.plos.org/ploscompbiol/articl...bi.1000467