*2.3. Peptide and Glycan Microarrays*

The whole proteome of SARS-CoV-2 (GenBank ID: MN908947.3) was mapped as 4883 spots of overlapping 15-mer peptides with a lateral shift of two AA on peptide microarrays, obtained from PEPperPRINT GmbH (Heidelberg, Germany). Glycan microarrays containing a selection of 135 glycans were produced at CIC biomaGUNE (San Sebastián, Spain) [13]. Patient sera were diluted 1:200 (peptide) or 1:100 (glycan) and incubated on the arrays overnight. Afterwards, IgG, IgM, and IgA serum antibody interactions were differentially detected with fluorescently labeled secondary antibodies. For details, see Supplementary Materials.
