Trial vaccine
The bivalent mRNA-1273.222 50 µg vaccine contains equal amounts of two mRNAs (25 µg of each mRNA sequence) that encode the prefusion-stabilized spike glycoproteins of the ancestral SARS-CoV-2 (Wuhan-Hu-1) and the Omicron variants (BA.4 and BA.5 have identical sequences and are designated as BA.4/BA.5). The monovalent mRNA-1273 50 µg original (Moderna COVID-19) vaccine)