Contact with COVID-19 (without RT-PCR test confirmation) was reported by a few children: one in the JIA group (positively tested for SARS-CoV-2 IgG and IgA antibodies), five in the control group (three positive for IgG and IgA antibodies, one in IgG only, and in two both results were negative). Here, CD79A is linked to juvenile idiopathic arthritis.