CPI is partnering with Excivion Ltd Cambridge to optimize the manufacture of its novel Zika vaccine antigen candidate, Zika-HX. CPI believes that Excivion’s technology could help to prevent future pandemics of deadly viruses by avoiding the adverse immune responses common in current vaccine candidates for Zika and related viruses.
 
Excivion has partnered with CPI to draw upon the company’s experience in the optimization and scale-up of biologics manufacturing processes. Over the next four months, CPI will proceed through a four-stage development program including technology transfer, characterization and upstream and downstream process development. Using its expertise and technology housed at the National Biologics Manufacturing Centre, Darlington, CPI will work to characterize the structure of the purified Zika-HX antigen. A scalable downstream purification method for the required product forms will be optimized. The work on upstream processing will assess whether it is possible to control the oligomerization state of the Zika-HX antigen within the existing bioprocess to maximize yield. CPI will have access to the initial bioprocessing data developed at ExpreS2ion.
 
Lucy Foley, Director of Biologics at CPI, commented, “Excivion’s flavivirus vaccine platform has the potential to produce safe and effective vaccines for viruses that represent some of the world’s greatest pandemic risks. We are looking forward to contributing to the Zika-HX project with our expertise in biologics manufacturing, helping Excivion to efficiently produce pure active antigens.”
 
Zika is a member of the Flavivirus genus that includes dengue, yellow fever and tick-borne encephalitis. In the case of dengue virus, infection with one serotype may result in the generation of antibodies that can increase disease severity following infection with a second serotype. This process is known as antibody dependent enhancement (ADE). There is a significant risk that the vaccines in development to protect against flaviviruses may sometimes cause ADE and actually worsen the effects of the disease that they are designed to prevent.
 
Excivion’s flavivirus vaccine platform involves cloaking the fusion-loop of the virus envelope protein with glycan molecules, which confers protection while avoiding the generation of the fusion-loop antibodies that cause ADE. For its proprietary Zika virus vaccine, Excivion is applying a Drosophila S2 insect cell-based protein production system, ExpreS2, from ExpreS2ion Biotechnologies ApS, Horsholm, Denmark. This will allow the company to obtain high quality recombinant Zika virus protein for the ongoing development project.