Table 1 presents a list of outbreak pathogens identified as high priority pathogens for medical countermeasures due to their high epidemic and pandemic potential.^37,38,39 Most of these diseases have MDx tests (reagent kits) that are commercially available, but appropriate only for use in high infrastructure research laboratories. In some cases, the MDx test has not been validated clinically or approved for diagnostic use (i.e. research-use-only kit), while in other cases, particularly for newer pathogens, MDx tests are available only as published protocols from trusted reference laboratories.^17,38,40 There is potential for available laboratory kits to be re-engineered for NPT/POC testing, including kits for viral haemorrhagic pathogens^41,42,43,44, arboviral diseases,^45,46,47,48 respiratory pathogens^49,50,51 and biothreat pathogens (including Disease X).^39,52,53

Tests for novel diseases are typically developed in academic or national reference laboratories which have the expertise, infrastructure and resources for rapid development and validation of MDx tests. These ‘in-house’ or laboratory-developed MDx tests are published and distributed as protocols from an internationally trusted source.^44,54,55,56 However, the test methods require a high level of expertise and are generally limited in deployment to other reference-level laboratories. Commercial products can enable broader deployment, where the MDx test is manufactured as quality-assured kits that contain all of the necessary pre-measured test reagents.

In the traditional development model, a commercial platform developer builds a portfolio of proprietary assays, using a cartridge specific to the developer’s instrument platform. The instrument, cartridge, reagents and consumables are manufactured by the platform developer and supported as a ‘sole source’ provision. Commercial development requires significant financial resources from the developer, with the cost of test development, manufacturing, clinical validation and regulatory approval generally considered to be an investment toward sustainable sales. Companies require some profit margin in order to sustain their business and further develop test menus. When the anticipated markets are small, such as for disease with limited or intermittent outbreaks, or where prices are constrained to the cost of goods (as is typical with global health/LMIC markets), then there is little incentive for commercial development. In many resource-constrained settings, alternative test options are not affordable or simply not available. To support rapid menu expansion during new or repeated outbreaks, a more flexible concept for outbreak pathogen test development is needed.

In LMIC settings, leveraging the existing diagnostic infrastructure is key to expanding the capacity for disease management and outbreak preparedness. Rather than requiring repeated de novo investment, existing platforms could be utilised for test menu expansion, building on the existing human resources, laboratory testing capacity and supply chains. A similar approach has seen success in the integration of tuberculosis- and HIV-testing at peripheral health centres.⁵⁷ For outbreak response, more flexible initiatives are needed to support rapid test development and deployment scenarios.

Here we describe a new open-source business model for MDx test development using existing platforms for NPT/POC diagnostic testing. As a key innovation, the open-source development model introduces an open-architecture cartridge designed to facilitate rapid development of tests by outside assay developers, where the platform developer provides an open, sterile cartridge that can be used by assay developers (academic or commercial) to rapidly prototype MDx tests for the existing platform. This development model leverages the strength of each developer, namely the available install base of a platform within relevant LMICs and the availability of reagent kits for the detection of outbreak pathogens, albeit for high infrastructure laboratory use. As noted in Table 2, this open-source development model can serve to decouple some of the risks for new test deployment.

This open-source model is intended to catalyse a more rapid approach to the development of diagnostic tests for decentralised or low-infrastructure settings, and to provide a more flexible approach to manufacturing tests for novel and endemic pathogens for LMICs through co-development (Table 3). Variations on the co-development partnership include collaborative research, test kit sub-contract manufacturing, and licensing or acquisition. These variations each require specific research and development and supply agreements, as well as marketing and product support agreements between the partners. In some cases, a highly successful development partnership could lead to downstream acquisition. Even in cases with limited sales, the ability to rapidly develop and deploy NPT/POC tests for novel pathogens is valuable in improving local outbreak response.

An open-source model for diagnostics can provide a more flexible and cost-effective approach to MDx deployment in peripheral settings, provided that commercial developers can find mutual benefit in a strategic partnership rather than traditional competition. The co-development model outlined above is intended to leverage the differential strengths between assay and platform developers by decoupling the investment risk for test menu expansion to include pathogens that may have limited but critically important deployment.

By leveraging existing assays and NPT/POC infrastructure, new tests can be rapidly re-engineered with a more cost-effective and ‘on demand’ approach for manufacturing. For the platform developer, a comprehensive assay menu expands the user base, which may provide more resilient and sustainable market volumes for diagnostic manufacturing. For the assay developer, their existing assay portfolio is expanded to include testing across a broad range of settings.^58,59,60,61 Designed to utilise existing LMIC resources, an acknowledged potential disadvantage of this business model is reduced competition in favour of entrenched player market stability and product availability. Novel molecular platforms must be evaluated, both for their potential implementation in LMICs, as well as their openness to work with partners in developing assays, particularly for outbreak-prone diseases.

To support this new development model, innovative partnerships and finance solutions are needed, especially for proactive development and commercial viability. Here, the role of product development partners can serve as both matchmaker and co-investor to incentivise co-development partnerships.⁶² The open-source model is currently being piloted by the Foundation for Innovative and New Diagnostics to partner diagnostic assay and platform developers in support of outbreak preparedness in the near term (2–5 years).⁵⁸ Similarly, this development model would also benefit from support from the global health community toward sustainable market commitments, pooled procurement mechanisms, and funding for test stockpiling to establish more sustainable supply chains and support long term commitments to diagnostic manufacturers.¹⁶ Some of these mechanisms are in place to address similar challenges in the vaccines sector and should be explored and adapted for diagnostics.⁶³

Despite the influx of interest at the onset of a new outbreak, it is more often the case that research and development costs for new diagnostics may be too high relative to market size to provide a sufficient incentive for product development, and sustained support can be particularly challenging, for pathogens that present seasonal or sporadic markets. Alternative business models for diagnostic development could help reduce the high costs associated with bringing a new pathogen test to market. An open-source development partnership model can combine the strengths of commercial developers to reduce development the cost and time to market, while supporting existing supply chain infrastructure, training and proficiency.^29,32

Certainly, there are additional upstream and downstream challenges for pathogen test development. For new or poorly understood outbreaks, there are uncertainties in pathogen identification, epidemiology and disease kinetics. Newly developed tests require additional resources for clinical validation, for which well-characterised specimens and calibration standards may be difficult to obtain.¹⁶ Commercial products also require international and/or in-country regulatory approval, though this may be a lower hurdle for assays that were previously validated as laboratory tests. Here, Product Development Partnerships can also serve as matchmakers to allow for sample sharing between research sites and developers with promising technologies, as well as to leverage in-country experience to support evaluation studies in LMICs that meet the requirements for regulatory approval.

The availability of appropriate diagnostics is a key feature for outbreak and epidemic preparedness. Early diagnosis of patients at initial point-of-care will enable timely patient and population interventions and support national surveillance systems for emerging and re-emerging diseases. Collaborative efforts are needed to develop NPT/POC diagnostics for all World Health Organization priority pathogens, to ensure access to high-quality diagnostics where testing is needed and to enable innovative funding mechanisms to support proactive development and market sustainability. We hope this article serves to encourage all diagnostic stakeholders (industry, academia, non-for-profit, non-governmental-organisations, governments) to foster partnerships in development and consider the open-source model early in the development of new diagnostics.