A Left: Schematic representation of VHH antibodies produced in E. coli as monomers or homo-trimeric fusions with the human collagen XVIII trimerization module. The VHH trimers match the three-fold rotational symmetry of the SARS-CoV-2 Spike protein. The molecular weight of the indicated modules is shown. Right: As an example, monomeric and trimeric forms of Re7H02 (a Re6B06 class member, Fig 1A) were analyzed by size exclusion chromatography (SEC, Superdex 200 column) coupled with multi-angle light scattering (MALS). The elution profiles (UV absorbance signal), as well as the calculated molecular weights (per slice), are plotted, and the average molecular weight is indicated. 