Commercial assays only detec >50 copies of plasma VL. Is it possible/likely (?) that the <50 copies of virus may be the ones that are drug resistant?

What are the reservoirs where dormant HIV resides and does the virus continue to do damage even when VL is <50? Can you please explain this...I wake up each morning, despite a VL <50 and a CD4 >700, wondering if my cognitive abilities might be compromised and/or that the virus may trigger meningitis or some other brain or neurological deficits if it still resides in cells, organs and the central nervous system. Any basis for this, even if a fairly low chance at these VL's and CD4 levels?

Finally, are the CD4's qualitatively the same as those in someone without HIV? Clinical treatment focuses on CD4 numbers and it is rare that anyone has a qualitative assessment on how the various CD4 cells (memory etc) tackle various viruses and other pathogens. Any studies on this?

Thanks for the wonderful service and advice you provide.

Given those numbers, you are not only immunologically intact, but cognitively as well. There may be areas of low level replication going on despite a plasma viral load < 50. Plasma viral load is only a measure of circulating virus being produced. It does not account for infected cells that have latent or nonreplicating virus within them. Current treatment does not really get rid of these long lived cells, but keeps the viral replication in check and the likelihood of high level resistance, with good adherence, is quite low. Measuring CD4 cell function, although doable, is very controversial. There are many kinds of tests, some measuring the same thing and some measuring different things. We do not yet know what is the best way to assess functional status of cells. With 700 CD4 cells, there is probably nothing to worry about.