CD4 and COVID-19: (15) evaluated the SARS-CoV-2-specific CD4+ T lymphocyte response and found that patients with only COVID-19 had a higher polyfunctional CD4+ T lymphocyte capacity (IFN-γ, IL-2 and TNF-α) and differences in the overall phenotype of CD4+ T lymphocytes specific against SARS-CoV-2 compared to patients with COVID-19 and aTB.