DPP4 and COVID-19: Specifically, the reduction in CD8+ effector memory T cells and altered expression of DPPIV in MAIT/NKT cells aligns with the broader literature on immune exhaustion and inflammatory dysregulation in severe COVID-19 Interestingly, our data suggest that recovery trajectories are not uniform across variants, with Delta variant convalescent patients showing a more stable immune response compared to Alpha variant patients.