Fig. 2

Characterization of WT and variant RBD mRNA and RBD mRNA-LNP vaccines. A Mutation sites of wild-type (WT), Delta, Omicron, and Hybrid RBD mRNA constructs. UTR untranslated region, SP signal peptide. B RNA identity and integrity of in vitro transcribed WT, Delta, Omicron, and Hybrid RBD mRNA measured by Fragment analysis. LM lower marker, RLU relative fluorescence units, nt nucleotide. C, D Binding capacity of WT and variant RBD expressed from mRNA (C) or mRNA-LNP (D) transfected cell supernatants to cells expressing human angiotensin-converting enzyme 2 (ACE2) or mouse ACE2 measured by flow cytometry. See also Additional file 1: Fig. S2