Defences against Disease X weakened by one missing ingredient: Trust

A meeting of world health authorities in May was meant to close one of the most important chapters in post-Covid global health diplomacy. Instead, member states of the World Health Organization (WHO) left Geneva empty-handed, although it gave them another year’s extension. The failure to clinch an agreement speaks to a central issue bedevilling efforts to fight the next pandemic – a lack of trust.

The shock of Covid-19 prompted WHO member states to adopt a landmark Pandemic Agreement in 2025 to avoid another disjointed global response. But a key component was left out: the Pathogen Access and Benefit Sharing (PABS) Annex.

Countries of the Global South wanted assurances that they would receive a fairer share of vaccines and treatments developed using pathogen data supplied by them. European and North American countries, especially those with stakes in big pharmaceutical companies, welcomed the data sharing but argued against being forced to share the benefits of their research. They claimed this would have a chilling effect on research and development.

On the surface, the deadlock in Geneva concerns technical questions on pathogen samples, genomic sequencing data, intellectual property, and the distribution of vaccines and diagnostics.

In reality, it reflects something far more fundamental. The inability to reach agreement is not primarily about science or logistics, but about trust. Five years after Covid-19, many countries remained unconvinced that their cooperation – through sharing pathogen data, for example – will be reciprocated with vaccines and treatments when the next crisis arrives.

Trust is critical if the world is to get its act together before the arrival of the dreaded Disease X – the as-yet-unknown pathogen that sets off the next pandemic. But the lack of it goes beyond the stalemate in Geneva, it exists within countries too. Just as governments became more sceptical of one another’s commitments, citizens in many societies have become more sceptical of the institutions responsible for safeguarding their health and well-being.

Together, these twin fractures are reshaping the foundations of modern public health.

When countries stop trusting one another

Global health has long depended on an implicit assumption that cooperation during crises ultimately serves everyone’s interests. The rapid sharing of disease information, early warning systems, and coordinated emergency responses were built on the belief that countries would work together when faced with a common threat.

Covid-19 tested that assumption and, in many ways, showed that it is flawed.

During the pandemic, countries experienced starkly unequal access to vaccines, diagnostics, and therapeutics. Export restrictions were imposed, and advance purchase agreements locked in supply for wealthier nations. Global calls for solidarity often struggled to translate into actions that produced equitable outcomes on the ground.

For many countries in the Global South, the experience left a bitter aftertaste: they participated in sharing data and supporting global response systems, but saw limited return when vaccines became available.

It is within this historical memory that the persistent failure in the PABS negotiations must be understood. What assurance exists that future sharing will lead to future access?

From this perspective, the deadlock is not simply a failure of diplomacy. It reflects a world in which countries increasingly prioritise their own interests and security over collective action.

The implications extend well beyond health. Across trade, technology, security, and geopolitics, countries are increasingly operating on the assumption that cooperation cannot be taken for granted and commitments cannot be taken at face value.

The growing use of tariffs, export controls, sanctions, and military deterrence reflects a broader international environment in which trust is in retreat. Global health, which depends fundamentally on the sharing of information, resources, and risk, is particularly vulnerable to this shift.

When citizens stop trusting institutions

The erosion of trust is not confined only to Geneva or diplomatic negotiating tables, but equally visible within countries, where public health systems are experiencing growing scepticism from the populations they serve.

In the United States, trust in public health guidance became deeply polarised during and after the pandemic, shaped by political identity as much as scientific evidence. Across parts of Europe, longstanding vaccine hesitancy was amplified by rapidly evolving guidance that many citizens interpreted as inconsistency rather than adaptive science. In other regions, from Latin America to parts of Asia, strained health systems and uneven communication further eroded public confidence.

Working in global public health over the past two decades, I have observed how profoundly this shift has altered the operating environment.

There is now a recurring pattern: when health guidance changes in response to new evidence, it is often interpreted not as the normal function of science, but as evidence of unreliability. The normal processes of scientific uncertainty, evolving evidence, and expert debate are increasingly being mistaken for failure.

This has been compounded by the politicisation of science itself, with health measures becoming markers of political identity. The result is a growing dissonance between how science operates and how it is perceived.

Science evolves through revision, while public trust often demands certainty.

This erosion of trust is reflected in broader societal indicators. Recent Edelman Trust Barometer surveys have highlighted growing public grievances and perceptions that governments, businesses, and elites increasingly serve narrow interests rather than broader societal well-being. Those expressing greater grievance also reported lower trust in major institutions, pointing to a widening disconnect between citizens and the institutions expected to act in their long-term interests.

Public health is particularly vulnerable because its greatest successes are often invisible. When outbreaks do not happen and diseases remain under control, people rarely notice. Yet the investments required to achieve those outcomes are immediate and highly visible.

Health consequences of mistrust

The consequences of declining trust are becoming increasingly visible in disease trends.

The resurgence of measles in several countries has become one of the clearest warning signs. Once considered a benchmark success of global vaccination efforts, measles had been eliminated or significantly reduced in many settings. Yet outbreaks have re-emerged across North America, Europe, and other regions as vaccination coverage has declined.

Measles is often described as the public health equivalent of the canary in the coal mine. Because it is one of the most contagious infectious diseases known, even small declines in vaccination coverage can trigger outbreaks.

Its return in countries that once had strong control therefore signals more than a disease-specific problem, but instead points to weakening confidence in routine immunisation systems and the institutions that deliver them.

If measles is the early warning signal, pertussis offers evidence that the signal is not isolated. Whooping cough has resurged in multiple countries where it was previously under control, including parts of North America, Latin America, and Europe. The tools to prevent it remain available, yet declining uptake has allowed transmission to re-establish itself. Unlike diseases driven by lack of access, its resurgence often reflects hesitancy and weakening confidence in routine vaccination.

Polio remains the most sobering example. Decades of progress towards eradication have been undermined in settings where distrust in vaccination campaigns intersects with political instability, misinformation, and historical grievances. In countries such as Pakistan and Afghanistan, eradication efforts have repeatedly encountered resistance rooted not only in logistical challenges, but also in mistrust of public authorities, suspicion of external influence, and persistent misinformation surrounding vaccination programmes.

Together, these diseases suggest that the re-emergence of vaccine-preventable diseases is increasingly less about technological capability and more about social acceptance.

In fact, the number of “zero-dose” children – those who have not received a single routine vaccine – remains significantly higher than pre-pandemic levels. In 2024, an estimated 14.3 million children globally were completely unvaccinated, about 1.4 million more than in 2019.

Health is not where the trust crisis begins

It is tempting to frame these developments, locally or globally, as a problem of misinformation or communication failure.

Certainly, misinformation has proliferated and been amplified by social media ecosystems, but it is rarely the root cause. Misinformation is perhaps more accurately described as an accelerant that spreads most effectively in environments where institutional trust is already weakened.

More fundamentally, trust in health is rarely generated within the health sector alone. It is shaped by broader perceptions of governance, fairness, and social contract. Populations that feel institutions are unresponsive, inequitable, or disconnected from their lived realities are less likely to trust guidance from those institutions, regardless of its scientific merit.

Health is therefore not the source of the trust crisis, but one of its most visible expressions.

Trust does not operate in neat compartments. When a country is seen as unreliable on issues such as security, trade, or international law, it becomes harder for others to trust its commitments in health as well. Credibility, once lost in one area, rarely stays confined there.

Governments cannot therefore expect confidence to remain intact if they selectively honour some international commitments while disregarding others. Trust in international cooperation is cumulative, and perceptions of inconsistency in one domain inevitably shape credibility in others.

Rebuilding trust

Rebuilding trust in global public health will therefore require more than just better messaging. It will require strengthening the conditions under which credibility is earned and sustained.

First, institutions must become more transparent about uncertainty. Scientific guidance will always evolve, and trust depends on explaining not only what has changed, but also why it has changed, through clear and consistent communication rather than one-off announcements during crises.

Second, institutions must demonstrate reliability through performance. Trust is earned not through rhetoric but through the consistent delivery of outcomes that improve people’s lives. Whether in healthcare, education, housing, public transport, or social services, confidence grows when institutions function effectively, respond competently to crises, and are visibly accountable when they fall short.

Third, governance must shift towards longer-term thinking. Building resilient societies operates on generational timescales, yet political incentives often operate on electoral ones. Sustained trust requires institutions that protect long-term investments in prevention, preparedness, and resilience from short-term political pressures.

Finally, fairness must be central. Trust is not only about competency, but also about whether populations believe that benefits and burdens are distributed equitably, both within and between countries.

At the global level, this means confronting the trust deficit exposed by Covid-19. The unresolved PABS negotiations are a case in point. Without credible assurances that pathogen sharing will lead to equitable access to vaccines and therapeutics, calls for solidarity will continue to face resistance.

For many countries, particularly in the Global South, the issue is not a lack of willingness to cooperate in principle, but a lack of trust that cooperation will be reciprocated in practice. This is precisely the tension that the PABS framework seeks to address, yet which has proven difficult to resolve in negotiations.

Any durable arrangement will therefore need to narrow the gap between promises and confidence. Countries will need clearer commitments on how benefits are shared, greater transparency in how vaccines and treatments are distributed, and agreed rules that cannot be easily changed when the next crisis arrives.

Trust as invisible infrastructure

Ultimately, trust functions as a form of invisible infrastructure which enables societies to function even under stress. When trust is strong, citizens accept difficult trade-offs, institutions can adapt to uncertainty, and countries can cooperate despite competing interests. When trust weakens, every challenge becomes harder to solve.

The temptation is to view declining trust in health as a problem for health ministries, public health agencies, or international organisations alone. This would be a mistake, since the trust that sustains public health is inherited from broader systems of governance, economic opportunity, social cohesion, and institutional legitimacy.

The resurgence of vaccine-preventable diseases, the growing difficulty of reaching global agreements, and the spread of misinformation should not be viewed as isolated phenomena. Instead, they point to a deeper challenge confronting societies around the world: a gradual erosion of confidence in the institutions designed to steward our collective future.

If trust is lost, no amount of scientific innovation, technological advancement, or diplomatic negotiation will be sufficient on its own. Rebuilding trust is therefore not merely a public health priority, but a societal one. The future of health may ultimately depend on whether we can restore confidence in the systems and institutions that make collective action possible.

We cannot allow mistrust today to end up producing disease tomorrow.