CD8A and COVID-19: Virus-specific memory T cell have been shown to persist for many years after infection.49 SARS-CoV-2-specific memory T cell responses can directed against the internal (nucleocapsid) and surface proteins (membrane and/or spike) in case of lacking antibodies.50 It is also found that mild cases have the higher proportions of SARS-CoV-2-specific CD8+ memory T cells than severe cases.51 Patients with COVID-19 showed different degrees of specific memory T clonotypic cell expansion or preservation, which may play a role in the case of another elimination of SARS-COV-2.