CD4 and HIV infectious disease: Between April 2019 and May 2020, 20 individuals were included in the study (90% men, mean age 57 years, 25 years since known HIV infection, CD4 cell count at inclusion 666 cells/mm3, CD8 count 766 cells/mm3, CD4/CD8 ratio 0.94, CD4 nadir 326 cells/mm3, 18 years on cART, 15% with prior history of AIDS, 6 cART regimens received).