Li MM, et al. - T-cell functionality and the expression of apoptotic/proliferation and activation/inhibition markers during acute SFTS viral (SFTSV) infection were determined. In parallel with T-cell depletion, higher annexin V and CD95 expression was observed in SFTS patients. Despite the observed apoptosis of T-cell, T-cell proliferation, activation and functional enhancement were apparent, indicating that these processes are involved in the complex protective response to SFTSV infection.