To examine whether the memory T cells established postnatural infection could provide sufficient protection against secondary viral infection, we collected PBMCs from three patients (C-COV19-005, C-COV19-045 and C-COV19-046) 6 months after infection and sequenced sorted CD8+ NP105–113-B*07:02-specific T cells. The gene discussed is CD8A; the disease is viral infectious disease.