Fig. 2

IFN-γ level after two doses of COVID-19 vaccines in individuals with or without prior SARS-CoV-2 infections. (a) The level of IFN-γ in response to the AG1 epitope. (b) The level of IFN-γ in response to the AG2 epitope. The dotted line indicates the cutoff value (0.2 IU/mL).