IFNG and infection: Infections were confirmed by SARS-CoV-2 positive PCR (n = 18), and/or a positive IFN-γ T cell FluoroSpot to SARS-CoV-2 nucleocapsid protein (n = 12, range 40–265, median 60 SFU/million PBMC)), and/or a ≥ 2-fold increase in MN titers between 12 and 18 months (n = 17, range 2–123 fold increase, median 3-fold increase).