PRE-CLINICAL EXPERIENCE WITH THE FluIDTM RAPID INFLUENZA TEST

Background: Nanogen has developed a novel 3^rd generation rapid POC assay, fluID™ Rapid Influenza Test, that demonstrates better sensitivity for influenza detection for types A and B with capability to differentiates H1 and H3 subtypes from H5 and other non-H1/H3 subtypes on a cost-competitive platform.  This sensitivity was gained by improving the assay chemistry using a unique multianalyte generic capture system employing a nucleic acid-like polymer, pRNA, implementing a fluorescent detection system, and adding a simple to use wash buffer that also improves sensitivity by reducing  the background signal in the assay.  

Methods:  A pre-validation design of the fluID^TM assay was used for all experiments to assess analytical performance.  The test’s Sample Collection Device (SCD) fully integrates a sample swab, virus lysis/extraction buffer, and assay reagents to facilitate sample collection, extraction of viral antigens from the swab specimen and transfer to the Test Device (TD).  This latter device contains the assay test strip and the wash buffer pouch for detection of viral analytes.  Multiple influenza (Type A strains from H1N1, H3N2, and H5N1 subtypes and Type B strains) and non-influenza virus dilution panels were prepared using a sample diluent buffer and viral strains that were purchased from several suppliers. The same virus dilutions were tested side by side with two currently marketed assays for a comparison of assay performance. H5N1 strains were tested in approved facilities for H5N1 containment.  Influenza virus testing was also performed on retrospectively collected nasal aspirate specimens.

Results:  The fluID assay showed very robust performance for all markers with better analytical sensitivity across experiments vs. the currently marketed assays. For Type A and Type B influenza strains, the fluID assay was 1 to 3 logs more sensitive then the currently marketed assays.  All tested live H5 strains from diverse clades were detected by the assay.  No false positive results were seen while testing presumed negative specimens or specificity panels.  

Conclusion:  The fluID assay demonstrated better sensitivity for detection of Type A and B influenza strains compared to other marketed assays and also showed good detection of Type A influenza subtypes H1, H3 and H5. Nanogen acknowledges support from the U.S. Department of Health & Human Services (HHS) through the CDC, and the Office of the Assistant Secretary for Preparedness and Response (ASPR) for advanced product development under Contract No. HHS200-2007-19345