Notice of Intent to Sole Source Serology DV-1-4 EDIII Reagents

The Centers for Disease Control and Prevention intends to award a sole source firm fixed price purchase order/contract to UNIVERSITY OF NORTH CAROLINA -CH Microbiology & Immunology for custom-produced biotinylated EDIII antigens for Zika virus and dengue virus serotypes 1–4 are specifically designed for the CDC flavivirus serologic assay development and validation using streptavidin-based capture and multiplex immunoassay platforms.

The requested HaloTag control antigen also provides a matched control for assessing nonspecific binding, assay background, and reagent-related signal. Published assay validation work using EDIII antigens demonstrated high sensitivity and specificity for distinguishing prior dengue and Zika virus exposure, supporting the technical need for these specialized reagents.

Commercially available whole-virus antigens, full-length envelope proteins, NS1 antigens, non-biotinylated recombinant EDIII antigens, and generic flavivirus assay reagents were considered. However, these alternatives do not meet the Branch’s technical requirements. Whole-virus and full-length flavivirus antigens contain conserved epitopes that can produce substantial cross-reactive antibody binding between dengue and Zika viruses, reducing assay specificity. Non-biotinylated or differently tagged antigens are not suitable substitutes because the current assay workflow depends on biotin–streptavidin capture for stable antigen immobilization, consistent antigen orientation, and reproducible assay conditions. Generic or off-the-shelf antigens also may differ in sequence, tag configuration, purity, lot consistency, or manufacturing method, which could introduce unacceptable variability and compromise comparability with existing validation data and ongoing laboratory protocols.

Use of alternative reagents would require additional optimization, bridging studies, and validation before they could be incorporated into existing workflows. This would delay laboratory testing and research activities, increase costs, and risk generating data that are not comparable with prior or ongoing assay development work. The selected supplier’s custom production of the required biotinylated EDIII and HaloTag control antigens is therefore necessary to maintain reagent consistency, assay performance, and continuity of the Dengue Branch’s serologic assay validation strategy.

This contract action is for supplies/services for which the Government intends to solicit and negotiate with only one source under the authority of Revolutionary FAR Overhaul 6.103-1 (SAP) ; under the authority of 41 U.S.C. 1901, as implemented in FAR subpart 12.102. Interested persons may identify their interest and capability to respond to the requirement or submit proposals.

This notice of intent is not a request for competitive quotations; however, all quotations/responses received within 15 days of the issuance of this notice shall be considered by the government. A determination by the government not to compete this proposed contract based upon responses to this notice is solely within the discretion of the government. Information received will normally be considered solely for the purpose of determining whether to conduct a competitive procurement. Any quotation/response should be emailed to contract specialist at email qsx8@cdc.gov by August 6, 2026 before 5pm EST.