During viral infections, antibodies and T cells act together to prevent pathogen spread and remove virus-infected cells. Virus-specific adaptive immunity can, however, also trigger pathological processes characterized by localized or systemic inflammatory events. The protective and/or pathological role of virus-specific T cells in SARS-CoV-2 infection has been the focus of many studies in COVID-19 patients and in vaccinated individuals. Here, we review the works that have elucidated the function of SARS-CoV-2-specific T cells in patients and in vaccinated individuals. Understanding whether SARS-CoV-2-specific T cells are more linked to protection or pathogenesis is pivotal to define future therapeutic and prophylactic strategies to manage the current pandemic.