ChAdOx1 nCoV-19 vaccine contains multiple proteins originating from the AV production process. (A) Four distinct lots of ChAdOx1 nCoV-19 vaccine were separated by 1D SDS-PAGE and proteins were visualized by silver staining. (B) Proteomics of ChAdOx1 nCoV-19 vaccine: iBAQ protein intensities and theoretical molecular masses of identified proteins. Protein intensities of vaccine lot 3 were calculated using the iBAQ algorithm (≥3 unique peptides per protein) and plotted against theoretical molecular mass. Human proteins are indicated in gray and ChAdOx1 proteins in blue. Furthermore, green dots mark human membrane proteins (UniProt annotation) and the single red dot shows the SARS-CoV-2 spike protein. Total amount of protein determined in 5 different lots ranged between 70-80 µg/mL, with human proteins constituting ∼43% to 60% of total proteins.