Background: The advanced research, development, and regulatory approval of medical countermeasures (MCMs) for emerging pathogens remains critical to national health security. We created a conceptual framework to assess the feasibility of generating pivotal data to support FDA regulatory approval of vaccines and therapeutics against known pathogens. Our framework is intended to guide key portfolio decisions on developing MCMs for emerging viral pathogens.
Methods: This framework draws on prior experience with MCM development programs, current FDA guidance, and insights from scientific, regulatory, and public health subject matter experts. We identified key requirements that impact the ability to generate pivotal data and assessed the likelihood of meeting these requirements based on current epidemiology, technical capabilities, and infrastructure. To demonstrate utility, we applied the framework to a subset of prioritized pathogens.
Results: We identified eight factors central to assessing the feasibility of advanced development and FDA approval of vaccines and therapeutics. These factors were used to evaluate seven emerging pathogens to illustrate how the framework may inform investment decisions across disease contexts.
Conclusions: This framework supports more efficient resource allocation by highlighting MCM candidates with the highest potential for FDA approval within existing regulatory paradigms. Given current conditions, vaccine development appears more feasible than therapeutics for the pathogens assessed, although regulatory pathways remain product- and context-specific. Close consultation with the FDA will be critical in defining appropriate regulatory strategies. This framework offers a structured, proactive approach to advance MCM development and strengthen national preparedness against emerging pathogens.
Keywords: emerging viral pathogens; medical countermeasures; national health security; vaccine and therapeutic development.
© The Author(s) 2025. Published by Oxford University Press on behalf of Infectious Diseases Society of America.