Design, immunogenicity and efficacy of a Pan-SARS-CoV-2 synthetic DNA vaccine

Here we have employed SynCon® design technology to construct a DNA vaccine expressing a pan-Spike immunogen (INO-4802) to induce broad immunity across SARS-CoV-2 variants of concern (VOC). Compared to WT and VOC-matched vaccines which showed reduced cross-neutralizing activity, INO-4802 induced potent neutralizing antibodies and T cell responses against WT as well as B.1.1.7, P.1, and B.1.351 VOCs in a murine model. In addition, a hamster challenge model demonstrated that INO-4802 conferred superior protection following intranasal B.1.351 challenge. Protection against weight loss associated with WT, B.1.1.7, P.1 and B.1.617.2 challenge was also demonstrated. Vaccinated hamsters showed enhanced humoral responses against VOC in a heterologous WT vaccine prime and INO-4802 boost setting. These results demonstrate the potential of the pan-SARS-CoV-2 vaccine, INO-4802 to induce cross-reactive immune responses against emerging VOC as either a standalone vaccine, or as a potential boost for individuals previously immunized with WT-matched vaccines. ### Competing Interest Statement C.C.R., V.M.A., R.K., K.S., J.T., B.S., D.E., J.W., I.M., A.D., Z.E., P.P., D.A. M.Y., J.F., R.F., M.V., J.J.K., L.M.H., S.J.R., T.R.F.S., K.E.B. are employees of Inovio Pharmaceuticals and as such receive salary and benefits, including ownership of stock and stock options, from the company. D.B.W. has received grant funding, participates in industry collaborations, has received speaking honoraria, and has received fees for consulting, including serving on scientific review committees and board services. Remuneration received by D.B.W. includes direct payments or stock or stock options, and in the interest of disclosure he notes potential conflicts associated with this work with Inovio and possibly others. In addition, he has a patent DNA vaccine delivery pending to Inovio. All other authors report there are no competing interests.