Since SARS-CoV-2 is an mRNA-based virus and mutations were expected, our strategy to eliminate possible emerging mutations was to select not the full sequence of the spike protein (most COVID-19 vaccine developers, including Pfizer-BioNTech and plant-based, Medicago’s VLP, which was approved for use by Health Canada, were targeted on the full-length S sequence) but rather a specific region of the S protein covering the RBD. Here, PROS1 is linked to COVID-19.