The developed combined vaccine against COVID-19, CCV-RBD, is an artificial particle containing the pVAXrbd DNA vaccine as a core, which encodes the receptor-binding domain of the S protein (Figure 1A), and on the surface the RBD protein is conjugated with the polymer PGS, as a particle envelope (Figure 2(B1)). The gene discussed is PROS1; the disease is COVID-19.