Early induction of SARS-CoV-2 specific T cells associates with rapid viral clearance and mild disease in COVID-19 patients

Tan, Anthony T; Linster, Martin; Tan, Cheewah; Bert, Nina Le; Chia, Wanni; Kunasegaran, Kamini; Zhuang, Yan; Tham, Christine YL; Chia, Adeline; Smith, Gavin James; Young, Barnaby Edward; Kalimuddin, Shirin; Low, Jenny GH; Lye, David; Wang, Lin-Fa; Bertoletti, Antonio

Virus-specific humoral and cellular immunity act synergistically to protect the host from viral infection. We interrogated the dynamic changes of virological and immunological parameters in 12 patients with symptomatic acute SARS-CoV-2 infection from disease onset to convalescence or death. We quantified SARS-CoV-2 viral RNA in the respiratory tract in parallel with antibodies and circulating T cells specific for various structural (NP, M, ORF3a and spike) and non-structural proteins (ORF7/8, NSP7 and NSP13). We observed that while rapid induction and quantity of humoral responses were associated with increased disease severity, an early induction of SARS-CoV-2 specific T cells was present in patients with mild disease and accelerated viral clearance. These findings provide further support for a protective role of SARS-CoV-2 specific T cells over antibodies during SARS-CoV-2 infection with important implications in vaccine design and immune-monitoring.