No significant differences were found in CD4 nadir, CD4 count at the time of pneumococcal infection, or proportion of patients with detectable viral load when PD occurred; however, a statistically higher CD4/CD8 ratio (medians: 0.6 vs. 0.4; RR 1.74; 95% CI 1.36–2.23; p < 0.001) was observed in severe patients. The gene discussed is CD8A; the disease is pneumococcal infection.