The global pandemic has resulted in unprecedented challenges for public health systems worldwide since the emergence of the novel coronavirus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in late 2019. A growing body of evidence has revealed that people who have recovered from COVID-19 may still be at risk of contracting SARS-CoV-2 again, raising questions about long-term immunity and the efficacy of vaccination campaigns. In this comprehensive review, we provide a comprehensive overview of the current evidence on COVID-19 reinfection, including the clinical characteristics, risk factors, immune response, and implications for public health measures, with a focus on recent research findings and relevant references