CD4 and COVID-19: Focusing on acute COVID-19 cases, SARS-CoV-2-specific CD4+ T cell response specificities (e.g., S, N, M, MP_R) and functionalities (e.g., IFNγ, TFH) grouped together in hierarchical clustering, with statistically significant correlations, indicating consistent CD4+ T cell response biology to SARS-CoV-2 across most acute COVID-19 patients (Figure 5A).