Zika Virus (ZIVK) is a mosquito-borne flavivirus that, originally, only caused small outbreaks across Africa and Asia, typically accompanied by mild illness. Recent outbreaks, however, have popped up worldwide and have been associated with severe complications including Guillain-Barré syndrome and neurological fetal abnormalities in women infected during pregnancy. The lack of therapeutic candidates as well as the widespread outbreaks and link of ZIKV infection to severe complications demands the urgent development of potent and safe vaccines.
Professors at the Biodesign Institute of Arizona State University have developed compositions of virus-like particles (VLPs) that display fusion proteins for creating Zika subunit vaccines. The fusion proteins have been produced in plants but could also be produced in other versatile expression systems. This VLP-based subunit vaccine was examined in mice and has been shown to be highly immunogenic, with two doses eliciting both strong humoral and cellular immune responses. Furthermore, the titers of ZIKV-specific and neutralizing antibodies exceeded the threshold that correlates with protective immunity against ZIKV.
The promising in vitro and mouse data demonstrate strong proof of concept and feasibility for further development of recombinant protein-based subunit vaccines against ZIKV with potency, affordability, and potentially enhanced safety.
• Zika virus subunit vaccine
Benefits and Advantages
• Highly immunogenic – two doses elicit both humoral and cellular immune responses specific to ZIKV
• Immunization induces anti-Zika neutralizing antibody titers in quantities that correlate with protective immunity
• No cross-reaction with Dengue Virus – reduced risk of antibody-dependent enhancement of infection
• Plant-based production platforms increase immunogenicity, stability and cost effectiveness
o Could also be used in other expression systems (yeast, E. coli, insect cells, mammalian cells, etc.)
o Average fusion protein accumulation of 1,824 µg/g leaf fresh weight which is one of the highest expression levels of recombinant proteins in plants
• Unlike DNA-based vaccines, there is no risk of genome insertion or associated oncogenesis by this vaccine
• Safer than inactivated virus and viral vector-based vaccines due to the virtual nonexistence of possible incomplete inactivation or unfavorable host responses to the vectors
• The antigen contains well-defined neutralizing epitopes and avoids epitopes with ADE pathological effects
• The fusion protein retains the proper folding of the native protein
For more information about the inventor(s) and their research, please see
Dr. Chen’s departmental webpage