Annelies Wilder-Smith, Sarah Osman
6 min
The International Health Regulations (IHR) function as a legally binding treaty for 196 countries, establishing the global framework for health security. A cornerstone of this framework is the Public Health Emergency of International Concern (PHEIC), a formal declaration used to identify extraordinary events that pose a risk to other states through international disease spread and require a coordinated global response. The decision to declare a PHEIC rests with the WHO Director-General, advised by an Emergency Committee of experts.
Since the IHR came into force in 2007, six events have been declared PHEIC:
While PHEIC declarations are powerful tools for mobilizing resources and streamlining emergency use authorizations for vaccines and diagnostics, they face significant limitations. The current binary "yes/no" system is often insufficient for events that require a graded or tiered response. Furthermore, the declaration process can inadvertently trigger disproportionate travel and trade restrictions, which may discourage countries from reporting outbreaks early. Experts suggest moving toward a multi-level PHEIC process, where each level is tied to objective epidemiological criteria and specific readiness actions, to improve global preparedness and minimize economic disruption.
RATIONALE: The International Health Regulations (IHR) have been the governing framework for global health security since 2007. Declaring public health emergencies of international concern (PHEIC) is a cornerstone of the IHR. Here we review how PHEIC are formally declared, the diseases for which such declarations have been made from 2007 to 2020 and justifications for such declarations. KEY FINDINGS: Six events were declared PHEIC between 2007 and 2020: the 2009 H1N1 influenza pandemic, Ebola (West African outbreak 2013-2015, outbreak in Democratic Republic of Congo 2018-2020), poliomyelitis (2014 to present), Zika (2016) and COVID-19 (2020 to present). Poliomyelitis is the longest PHEIC. Zika was the first PHEIC for an arboviral disease. For several other emerging diseases a PHEIC was not declared despite the fact that the public health impact of the event was considered serious and associated with potential for international spread. RECOMMENDATIONS: The binary nature of a PHEIC declaration is often not helpful for events where a tiered or graded approach is needed. The strength of PHEIC declarations is the ability to rapidly mobilize international coordination, streamline funding and accelerate the advancement of the development of vaccines, therapeutics and diagnostics under emergency use authorization. The ultimate purpose of such declaration is to catalyse timely evidence-based action, to limit the public health and societal impacts of emerging and re-emerging disease risks while preventing unwarranted travel and trade restrictions.
Alex: The measles resurgence is an interesting stress test here. That clearly crossed borders, but no PHEIC was declared.
Sam: Right, and that's where the governance logic becomes particularly strained. Measles didn't meet the "threat to international trade and travel" criteria that the IHR uses as a trigger. So a pathogen causing genuine cross-border public health harm didn't qualify, because the framework is partly built around economic disruption rather than epidemiological risk. The paper's argument is that we're running a 21st-century surveillance problem on 2005-era decision logic.
Alex: And with no real enforcement mechanism, even a declaration doesn't guarantee compliance. [[RP_SECTION:governance-and-political-friction|Governance and Political Friction]]
Sam: It relies on the goodwill of member states. That's the second structural weakness. The tiered system the paper advocates would need to be paired with objective, pre-specified criteria for each tier — a scoring rubric based on transmissibility, case fatality rate, geographic spread, and healthcare system capacity — so the committee's decision is less exposed to political pressure from affected states. The goal is to reduce the friction that currently paralyzes the committee at exactly the moment when speed matters most. [[RP_SECTION:limitations-of-governance-reform|Limitations of Governance Reform]]
Alex: Where does the argument run into trouble? A tiered system sounds reasonable in principle, but the political economy seems just as hard to navigate.
Sam: That's the honest limitation. This is a governance review, not an empirical test of a tiered system. There's no counterfactual — we can't run the 2014 Ebola response again under a different framework and measure the outcome. The argument rests on the plausibility of the mechanism: that lower-stakes early tiers would reduce reporting hesitancy. But whether member states would actually report earlier, or simply game the lower tiers to avoid triggering the higher ones, is an open question the review doesn't resolve.
Alex: So the core claim is structurally sound, but the evidence base is necessarily observational and retrospective.
Sam: Yes. The paper is making a design argument from failure cases — Ebola 2014, DRC 2018, measles — rather than from a controlled comparison. That's the appropriate method for a governance problem of this kind, but it means the causal claim that a tiered system would have changed outcomes is inferential. What the paper does establish clearly is that the current binary structure has a predictable failure mode, and that failure mode has recurred across multiple outbreaks. That's a meaningful pattern even without a randomized trial of international health law.
Alex: The framework is producing the same failure repeatedly, and the mechanism for why is well-specified. That's a reasonable basis for a reform argument.
Sam: And the reform itself isn't novel — tiered alert systems exist in other domains, from nuclear threat levels to hurricane categories. The question is whether the political will exists to renegotiate the IHR toward something more graduated. The paper is essentially making the case that the cost of not doing so keeps showing up in delayed declarations and lost containment windows. Thanks for listening to ResearchPod.