Interestingly, a pronounced immunodeficiency (current CD4 count < 350/μL) was found to be associated with an increased risk for severe COVID-19 (aOR 2.85, 95% CI: 1.26–6.44, p = 0.01) and low nadir CD4 counts associated with an increased mortality [24]. This evidence concerns the gene CD4 and immunodeficiency disease.