Such findings are substantiated by the empirical observations, wherein mice (BALB/c and C57BL/6) immunized with Venezuelan equine encephalitis replicon particles (VRPs) expressing the SARS-CoV-2 S protein (VRP-S) showed a 1000 times reduction in SARS-CoV-2 titres by day 1 post infection (d.p.i) (3 weeks post vaccination). This evidence concerns the gene PROS1 and infection.