Figure 3.

Role of T cells during coinfection with viruses, bacteria, and parasites. In SARS-CoV-2 coinfection with HBV, exhausted T cells are caused by HBV infection and subsequently countered with SARS-CoV-2 infection cytokine storms. In HIV coinfection, CD4⁺ T cells are corrupted, leading to exacerbated patient outcomes. Influenza coinfection decreases neutralization antibody efficacy and increases ACE2 receptors, overall boosting SARS-CoV-2 infection. For Mtb coinfection, both infections will affect the lung tissue, resulting in respiratory failure. In coinfection with parasites, Th2 and Treg cells are induced to suppress the immune system and ameliorate the intestinal inflammation severity of SARS-CoV-2.