I noticed in the published version on Nature Med it has an extended discussion on the “glycan shield”. The analysis done in this correspondence only refers to one O-linked glycan motif. The “glycan shield” mostly refers to N-linked glycans, which are quite abundant in beta coronavirus and are the major constituents of the “glycan shield”. So there is a big jump in the discussion which may lead to confusion. I just post an initial analysis here in collaboration with David Robertson, and will post a full analysis on this later. 02_surface.pdf (170.9 KB) 02_surface_wuhan_ref_O_linked.pdf (121.3 KB)