At present, the COVID-19 vaccines that have been successfully developed and marketed include inactivated vaccines (inactivated SARS-CoV-2), virus-like particle vaccines (virus particles without nucleic acid), subunit vaccines (in vitro-expressed spike (S) protein or receptor binding domain (RBD)), viral vector vaccine (replication-deficient engineered virus carrying S protein or RBD mRNA), DNA vaccines (S protein or RBD DNA sequence), mRNA vaccines (S protein or RBD RNA sequence), and live attenuated vaccines. Here, PROS1 is linked to COVID-19.