The median CD4 cell count at any OI diagnosis was 121 cells/μL, (IQR, 24–268 cells/μL), with a median of 14 cells/μL (IQR, 4–90 cells/μL) in patients with cryptococcal meningitis, 102 cells/μL (IQR, 8–189 cells/μL) for oral candidiasis, 140 cells/μL (IQR, 45–253 cells/μL) for tuberculosis and 268 cells/μL (IQR, 128–324 cells/μL) in patients diagnosed with herpes zoster. This evidence concerns the gene CD4 and herpes zoster.