COVID-19 vaccination programmes are ongoing worldwide. Neutralizing antibodies are thought to be key for host protection against COVID-19; however, strategies that focus only on neutralizing antibodies may not be sufficient to cope with the pandemic in the longer term owing to the decay of antibody titres and the emergence of antibody-escape variants of SARS-CoV-2. Here, we describe the protective roles of T cells in COVID-19 and the conservation of T cell epitopes in SARS-CoV-2 variants of concern, and discuss the potential contribution of T cell-oriented strategies to controlling the COVID-19 pandemic.