Therefore, Del-X is predicted to weaken the immune response against the pathogen, compared to the response against wild type Mtb. The patient’s immune system was severely compromised by his HIV infection, as evidenced by the low CD4 counts (about 80 per μL), low CD4/CD8 ratio (10%), and high viral load (near 350,000 and 900,000 per mL) measured in 2017 and in 2018, respectively. Here, CD4 is linked to HIV infectious disease.