Novel assay detects Zika, differentiates from dengue and other flaviviruses

A collaboration between Swiss antibody therapeutics firm Humab BioMed and the University of California, Berkeley has given rise to an antibody-based assay which identify Zika infection, even differentiating it from other flaviviruses such as dengue.

The project was a collaborative effort across laboratories in the UK, Switzerland, Italy, Brazil and Nicaragua, investigating characterised samples collected from joint long-term studies. Both dengue-infected samples and non-infected samples were examined.  

The assay is distinct from other existing versions in that it affords a wider window of opportunity and its ability to differentiate between flaviviruses is much more effective. It could mean medical professionals are able to much more accurately measure the prevalence of Zika infections and examine the neurological complications associated with the virus in much more detail.

Humab was able to use its proprietary CellClone technology, to create a ZIKV non-structural protein 1 (NS1)-specific human monoclonal antibody. The new assay was born from this – it is a competitive ELISA format and works by identifying the presence of plasma or serum antibodies in immune patients who block the binding of a labelled monoclonal antibody to coated Zika virus NS1. For this reason, it is named NS1 blockade-of-binding (BOB) ELISA. It is also deemed to be cost-effective to use – a huge bonus given that the areas of highest need for the treatment are developing nations.

"These results support that the antibody-based assay that we have developed is highly effective in detecting both recent and past Zika virus infections and in discriminating Zika from other flavivirus infections," commented Dr Davide Corti, Chief Scientific Officer of Humabs BioMed. "This novel assay has the potential to become an effective, simple and low-cost solution for Zika surveillance programmes, prevalence studies and clinical intervention trials in flavivirus-endemic areas."

Lead researcher Professor Eva Harris, Division of Infectious Diseases and Vaccinology, School of Public Health, University of California, Berkeley, added: "It is very exciting to finally have a robust, high-throughput assay with such high sensitivity and specificity to distinguish Zika virus infections in dengue-endemic countries; we have already applied it to large age-stratified serosurveys and spatial analysis of Zika virus infection in Nicaragua, advancing scientific research while providing critical data to public health authorities in real time."

Matt Fellows