Conclusion
Dissecting the role of T cell immunity in SARS-CoV-2 infection is the base for effectively guiding clinical therapy and designing vaccines. Functional optimization of activated T cells, effector T cells, memory T cells, Tregs, NKT, γδT and MAIT cells is critical to resolve SARS-CoV-2 infection. However, SARS-CoV-2 infection disturb the interaction of innate and adaptive immunity including decreased T cell number, impaired T cell proliferation/differentiation/survival, highly activated and exhausted status, and improper cytokine secretion and chemotaxis. The altered T cell functions and excessive inflammation contribute to severe symptoms of COVID-19. Therefore, T cell-based therapeutic approaches, including enhancing virus-specific T cell responses, reverting T‐cell exhaustion and alleviating inflammatory cytokine storm, should be considered therapeutic strategies for improving clinical outcomes.