Fig. 2: S protein antigenicity.

a Radar plots showing luminescence intensities measured with cell-based ELISA (CBE) and median fluorescence intensity (MFI) measured with flow cytometry (“Flow”). For CBE, cells were transfected with DNA constructs, whereas for flow cytometry cells were transduced with Ad26 vectors. Luminescence and MFI were calculated as an average of a duplicate and the MFI were normalized (by multiplying with a factor 342) to have the highest intensity the same as the highest CBE luminescence intensity. The outer ring of the circles represents a value of 10,000,000. Conv. serum stands for convalescent serum. S.dFurin and S.PP-PR were measured only with CBE. b ACE2 binding measured with CBE (n = 2). Data are represented as mean + s.d. c Average luminescence intensities measured with CBE or MFI measured with flow cytometry of neutralizing ligands and antibodies divided by that of non-neutralizing antibodies. The black horizontal dashed line indicates the height of the neut:non-neut ratio for S in CBE and the gray one for S in flow cytometry. d Western blot analysis for expression from Ad26 vaccine vectors encoding tPA.S, tPA.S.PP, S, tPA.WT.S, and S.PP in MRC-5 cell lysates under non-reduced conditions using a human monoclonal antibody (CR3046). Ad26.Empty was included as negative control.