This modified mRNA encodes the South African variant of the spike glycoprotein receptor binding domain (RBD, Arg319-Phe541) from severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2). This RBD mutant has K417N, E484K and N501Y mutations in the S glycoprotein RBD as compared to the SARS-CoV-2 reference sequence (GenPept: QHD43416).

• 5' Cap: Capped with ARCA (Anti Reverse Cap Analog, m7(3'-O-methyl)-G(5')ppp(5')G, Cap 0) or CleanCap AG (m7G(5')ppp(5')(2'OMeA)pG, Cap 1)
• 5’-UTR: derived from human alpha-globin RNA with an optimized Kozak sequence
• Codon Optimization: Human
• Mutations: K417N, E484K and N501Y
• Nucleotide Modifications: mRNA modified with both Pseudo-UTP and 5mCTP
• 3’-UTR: comprises two sequence elements derived from the amino-terminal enhancer of split (AES) mRNA and the mitochondrial encoded 12S ribosomal RNA to confer RNA stability and high total protein expression.
• PolyA: 180 nt