IFNG and COVID-19: Similarly to previously published data [11], we found a strong increase of the cytokines IL-15, IL-6, TNF-α and IFN-γ as well as of the chemokine CXCL10 1 day post-immunization in the CoVonly group receiving only the third booster dose of COVID-19 vaccine as well as in the FlubeforeCoV group after COVID-19 vaccination.