Due to the association of full-length S protein from SARS1 and MERS with enhancement of viral infection in several preclinical systems [26,27,28,29] and serious pulmonary immune pathology in experimental animals [29,30,31,32,33], we designed an RBD vaccine antigen comprising amino acids 331–632 of the S1 component of the SARS-CoV-2 glycoprotein S (Figure 1A) [24]. The gene discussed is PROS1; the disease is viral infectious disease.