S proteins for both viruses have served as vaccine antigens that could elicit antibodies to prevent virus entry by blocking the binding of RBD to ACE2 (Hoffmann et al. 2020), and all the leading COVID-19 vaccines currently in clinical trials, including the mRNA vaccines, use the S protein to elicit immunity (Haynes et al. 2020). This evidence concerns the gene PROS1 and COVID-19.