PROS1 and COVID-19: Only one of these 15 vaccines was an mRNA-based vaccine (S protein) produced in the United Kingdom for SARS-CoV2, whereas Wang et al. (2020) reviewed 13 COVID-19 vaccines of which two are mRNA-based vaccines, the first developed by Moderna/NIH and the second by Pfizer/BioNTech, the vaccines candidates are mRNA1273 and BNT162b2.