PSMD1 and COVID-19: Seroconversion (i.e. presence of S1-reactive antibodies) was assessed in infection-naive patients (defined as no history of COVID-19; negative SARS-CoV-2 RT-PCR, and negative S1-reactive antibodies prior to vaccination) at baseline, 2-4 weeks post-first, and 2-4 weeks post-second vaccine dose (Figure 1a).