Japan-based Takada Vaccines, Inc. has scheduled a poster presentation for November 19, 2021, during the annual American Society of Tropical Medicine and Hygiene digital meeting.
This presentation, led by Erick Perez-Guzman, Mayuri Sharma, Ralph Braun with Takeda, will discuss how Zika virus-specific antibodies that can be distinguished from antibodies to other flaviviruses (FV), which will improve differential diagnosis and support the development of Zika vaccines in flavivirus-endemic regions''''Zika virus (ZIKV) re-emergence and spread into flavivirus endemic regions have caused serodiagnostic challenges due to antibody cross-reactivity among the FVs.
Currently, there are no viral envelope protein-based assays available to quantitatively measure ZIKV-specific antibody responses in individuals with prior FV exposure.
These presenters describe the development of a ZIKV-specific competitive microsphere-based immunoassay to support ongoing clinical trials of Takeda's purified inactivated ZIKV vaccine (PIZV) candidate.
The assay design allows ZIKV-specific antibodies present in plasma or serum samples to compete with the binding of an anti-ZIKV EDIII monoclonal antibody to a specific epitope on ZIKV virus-like particles coupled to Luminex magnetic microspheres. ZIKV-specific antibody levels in the presence or absence of antibodies to other FVs can then be determined in the samples.
Human and non-human primate (NHP) sample panels exposed to different FVs, including ZIKV, dengue virus (all four serotypes), Yellow Fever virus, Saint Louis Encephalitis virus, West Nile virus, Japanese Encephalitis virus, and Tick-Borne Encephalitis virus, were assessed using this assay.
The assay quantified ZIKV-specific antibodies in all presumptive or confirmed ZIKV or PIZV-immune samples, while all other FV-immune samples were negative in the assay.
Of note, the assay was also able to quantify PIZV-elicited ZIKV-specific antibodies in the presence of cross-reactive antibodies from prior FV vaccination.
In summary, these presenters say our data suggest that the assay can differentiate ZIKV-specific antibodies from antibodies to other FVs elicited by natural infection or vaccination.''
Availability of a ZIKV-specific antibody-based immunoassay will improve differential diagnosis, serosurveillance and support the development and implementation of ZIKV vaccines in FV endemic regions.
Takeda's Zika vaccine candidate (TAK-426; PIZV) is a purified, inactivated, alum-adjuvanted, whole Zika virus vaccine candidate conducting clinical studies.