Comparing the T-cell response generated by COVID-19 antigens between the two vaccine types, our data showed a twofold increase in T-cell response to S1-RBD-CD4+ T-cell epitopes (Ag1) in patients vaccinated with the BNT162b2 compared to those who were primed with BBIBP-CorV vaccine. The gene discussed is CD4; the disease is COVID-19.