PSMD1 and idiopathic pulmonary fibrosis: In all analyzed groups, a significant increase in the concentration of anti-S1 IgA antibodies was observed between the 1st and 2nd course of vaccination (p=0.003 for IPF patients without previous exposure to SARS-CoV-2; p=0.0001 for the control group and p=0.03 for convalescent IPF sufferers), as expected.