Approximately 20% of HIV patients with severe CD4+ T cell deficiency develop an IRIS after commencing ART, which presents at a median time of 10-16 days for TB-IRIS, while approximately 20% of people with symptomatic SARS-CoV-2 infection develop severe COVID-19 at about 10 days after symptom onset. This evidence concerns the gene CD4 and congenital T-cell immunodeficiency.