Figure 1.

Rationale for the SCV Vaccine Platform Technology

(A) VACV multiplication in the cytoplasm of host cells is able to produce infectious viral progeny as VACV encodes the essential assembly protein D13. (B) Targeted deletion of D13L in SCV prevents virion assembly, rendering SCV multiplication-defective (unable to generate infectious progeny). (C) In trans provision of D13 in the CHO-based SCS line rescues viral assembly, allowing production of progeny for vaccine manufacture. Expression of the host-range protein CP77 allows SCV (or VACV) multiplication in CHO cells. (D) After delivery of SCV-CHIK to a vaccine recipient, the genome of SCV-CHIK is amplified and late gene expression drives production of the CHIKV structural proteins (vaccine antigen). In the absence of D13 protein, no SCV-CHIK viral progeny are generated.