Vaccinia-based systems have been extensively explored for the development of recombinant vaccines. Herein we describe an innovative vaccinia virus (VACV)-derived vaccine platform technology termed ‘Sementis Copenhagen Vector’ (SCV), which has been rendered multiplication-defective by a targeted deletion of the essential viral assembly gene, D13L. A SCV cell substrate (SCS) line was developed for production of SCV vaccines by engineering CHO cells to express D13 and the VACV host-range factor CP77, as CHO cells are routinely used for manufacture of biologics. To illustrate the utility of the SCV vaccine platform technology, a SCV vaccine against both chikungunya and Zika virus (SCV-CHIK/ZIKA) was developed and shown to be multiplication-defective in a range of human cell lines and in immunocompromised mice. A single vaccination of mice with SCV-CHIK/ZIKA was able to induce neutralising antibody responses specific for both viruses, they were provided complete protection in viral challenge studies, prior infection with chikungunya virus did not influence Zika virus vaccine responses and the offspring of vaccinated pregnant mice were protected from Zika virus infection.