The Pathogens That Could Trigger the Next Pandemic

The next pandemic could be closer than we think, as the World Health Organization (WHO) unveils its updated list of over 30 high-risk pathogens that pose significant threats to global health. This “priority pathogens” list, which includes viruses such as influenza A, monkeypox, and the Nipah virus, serves as a crucial tool to guide the development of vaccines, treatments, and diagnostics. Ana Maria Henao Restrepo, leader of WHO’s R&D Blueprint for Epidemics team, explains, “The prioritization process helps identify critical knowledge gaps that need to be addressed urgently and ensures the efficient use of resources.”

This new list reflects the dynamic nature of global health risks, as it expands on previous efforts from 2017 and 2018 that identified roughly a dozen pathogens. Now, factors like climate change, urbanization, and deforestation have heightened the risk of zoonotic diseases and emerging viruses jumping to humans. The WHO worked with over 200 scientists, evaluating evidence on 1,652 pathogen species, to create a comprehensive list that includes entire families of viruses and bacteria.

From the inclusion of zoonotic viruses like Nipah to concerns about smallpox despite its eradication, the updated list underscores the urgency of pandemic preparedness. It is not merely an inventory of potential threats but a roadmap for action, highlighting where resources should be focused to prevent the next global outbreak. As the list continues to evolve, so too must our collective efforts to stay ahead of these dangerous pathogens.

Understanding the WHO’s Priority Pathogen List

The next pandemic is not a matter of “if” but “when,” and WHO’s updated priority pathogen list serves as a critical tool in preparing for future outbreaks. But what exactly is this list, and why is it so vital? The priority pathogen list is a carefully curated catalog of viruses and bacteria that have the potential to cause global public health emergencies. These pathogens are selected based on three main criteria: their ability to spread quickly (transmissibility), their severity (virulence), and the lack of available treatments or vaccines.

Ana Maria Henao Restrepo, who leads WHO’s R&D Blueprint for Epidemics, emphasized its significance, stating, “The prioritization process helps identify critical knowledge gaps that need to be addressed urgently and ensures the efficient use of resources.” By identifying these gaps, the list provides a foundation for scientists, healthcare professionals, and governments to allocate resources effectively toward research, vaccine development, and pandemic preparedness.

How Has the List Evolved Over Time?

First introduced in 2017 and updated again in 2018, the earlier versions of the list identified a dozen pathogens. However, the recent update has expanded its scope significantly. Over 200 scientists spent two years evaluating evidence on 1,652 pathogens to determine which pose the greatest threats. This thorough evaluation broadened the list to include entire families of viruses and bacteria, making it the most comprehensive yet.

Unlike previous versions that focused on individual viruses like SARS and MERS, this list includes broader groups such as the Sarbecovirus family, which encompasses SARS-CoV-2 (the virus behind COVID-19). This shift underscores the need to prepare not only for known threats but also for related pathogens that could evolve and emerge unexpectedly.

Why the List Matters for Global Health

The importance of this list lies in its ability to guide global health strategies. It helps prioritize research, ensuring that limited resources are used to address the most pressing threats. For example, pathogens like the Nipah virus, which has caused outbreaks in India, and monkeypox, which sparked a global outbreak in 2022, now have greater attention due to their inclusion. WHO’s efforts to highlight these pathogens aim to save lives by fostering early detection and rapid response strategies.

By maintaining and regularly updating this list, WHO ensures that the global community remains vigilant and prepared. The list serves as both a warning and a call to action, urging countries to invest in surveillance systems, diagnostic tools, and vaccines to prevent the devastation of another global pandemic.

The Role of Global Changes

The escalating risk of a next pandemic cannot be fully understood without examining the impact of global changes. The spread and emergence of many high-risk pathogens are tightly linked to transformations in the environment, human activity, and the interconnectedness of our world. Climate change, urbanization, deforestation, and increased international travel are some of the most significant factors driving the rise in zoonotic diseases and other infectious outbreaks.

Climate Change and Disease Transmission

Climate change is reshaping the habitats of many animal species, forcing them into closer contact with human populations. This shift increases the likelihood of zoonotic spillovers, where diseases jump from animals to humans. For example, warming temperatures have expanded the range of mosquitoes that transmit diseases like dengue and malaria, exposing new regions to outbreaks. Similarly, changes in rainfall patterns can foster environments for waterborne pathogens, such as cholera, to thrive.

Urbanization and Population Density

The rapid growth of urban areas creates conditions that can accelerate the spread of infectious diseases. Crowded cities, inadequate sanitation, and high population density provide fertile ground for viruses and bacteria to spread quickly. Urbanization also increases human-wildlife interaction, as expanding cities encroach on natural habitats. This dynamic has already been linked to the emergence of diseases like the Nipah virus, which originated in bats but has increasingly affected humans as their habitats overlap.

Deforestation and Habitat Disruption

Deforestation, often driven by agriculture and industry, disrupts ecosystems and brings humans into closer contact with wildlife. As forests are cleared, species that were once isolated are forced into human settlements, increasing the chance of zoonotic transmission. Diseases like Ebola, for example, have been linked to regions experiencing significant deforestation. These disruptions also reduce biodiversity, weakening natural disease regulation and making outbreaks more likely.

Global Connectivity and Travel

International travel and trade have made the world more connected than ever, enabling diseases to spread at unprecedented speeds. Pathogens that were once confined to specific regions, such as monkeypox or dengue, now have the potential to become global issues. A single infected traveler can unknowingly carry a virus across borders, as seen during the early stages of the COVID-19 pandemic. This connectivity demands constant vigilance and rapid response mechanisms to prevent localized outbreaks from escalating globally.

By acknowledging the profound impact of these global changes, WHO’s updated list of priority pathogens not only identifies risks but also highlights the underlying factors driving them. Addressing these root causes requires coordinated action across sectors, from environmental conservation to urban planning, to reduce the likelihood of future pandemics.

 Behind the Scenes of the List’s Development

Creating WHO’s updated priority pathogens list was a monumental task that involved rigorous scientific evaluation and collaboration among global experts. The process was not merely a bureaucratic exercise but a detailed, evidence-based effort to identify and prioritize the most significant threats to global health. Understanding how this list was developed provides crucial insight into its importance and credibility.

The Scientific Effort

More than 200 scientists from around the world worked together for two years to evaluate a staggering 1,652 pathogen species. The evaluation process involved reviewing data on the transmissibility, virulence, and potential for widespread outbreaks of each pathogen. WHO aimed not only to identify immediate risks but also to anticipate future threats that could emerge due to global changes. This scientific rigor ensures the list is comprehensive and forward-looking, capable of guiding public health strategies for years to come.

One key shift in this update is the focus on entire families of pathogens rather than just individual viruses or bacteria. For instance, instead of listing SARS and MERS as specific threats, the broader Sarbecovirus and Merbecovirus families were included. This approach reflects the understanding that closely related pathogens often share similar risks and characteristics, making it essential to monitor their potential to evolve and cause outbreaks.

Broader Scope and Inclusion

The expanded list now includes over 30 priority pathogens, significantly more than the dozen identified in the 2017 and 2018 versions. This broader scope reflects an acknowledgment of the increasingly complex global health landscape. Additions such as rodent-borne viruses, influenza A subtypes, and bacterial threats like cholera and plague highlight the need for a more inclusive approach. These pathogens were chosen based on their potential to cause pandemics under the right conditions, even if they are currently confined to specific regions.

The Nipah virus, for example, remains on the list due to its high fatality rate and history of sporadic outbreaks in South Asia. Similarly, the inclusion of monkeypox and smallpox underscores concerns about re-emerging diseases and the potential for bioterrorism. By identifying these risks early, WHO aims to stay ahead of potential threats and provide the scientific community with a clear direction for research and development.

Collaborative Approach

The development of the list was a global effort, bringing together virologists, epidemiologists, public health officials, and other experts. This collaborative approach ensures that the list reflects diverse perspectives and expertise, making it a robust tool for guiding public health policies. It also emphasizes the importance of international cooperation in addressing health threats that know no borders.

The process of creating the list is not static; it is designed to evolve as new information becomes available and as global conditions change. Regular updates ensure that the list remains relevant and effective in addressing emerging challenges. This adaptability is crucial for maintaining global preparedness against the next pandemic.

Implications for Global Health Preparedness

The WHO’s updated priority pathogens list is more than a catalog of potential threats—it is a strategic roadmap for enhancing global health preparedness. By identifying high-risk viruses and bacteria, the list provides clear guidance on where to focus resources, research, and public health initiatives to prevent the devastation of the next pandemic.

Guiding Vaccine and Treatment Development

One of the most critical implications of the list is its role in driving research and development. With limited resources, it is essential to prioritize pathogens that pose the most immediate and significant threats. The list helps streamline global efforts by encouraging investment in vaccines, treatments, and diagnostics for these diseases. For example, the inclusion of influenza A viruses and monkeypox has already spurred international initiatives to develop effective vaccines and therapies.

The list also draws attention to pathogens for which no treatments currently exist, such as the Nipah virus and certain rodent-borne diseases. By highlighting these gaps, it prompts scientific communities and pharmaceutical companies to prioritize innovative solutions to combat these threats.

Improving Surveillance Systems

Another key benefit of the priority pathogen list is its role in strengthening global surveillance systems. Monitoring the spread and evolution of these pathogens is essential for early detection and rapid response. For instance, the inclusion of coronaviruses such as SARS-CoV-2 and Merbecovirus ensures that researchers remain vigilant in tracking mutations that could lead to new outbreaks. Enhanced surveillance can help contain localized outbreaks before they escalate into global crises.

Promoting International Collaboration

The interconnected nature of global health means that no country can address pandemic risks alone. The WHO list fosters international cooperation by providing a shared framework for understanding and responding to threats. It encourages countries to share data, collaborate on research, and coordinate public health responses. The lessons learned from the COVID-19 pandemic have underscored the importance of such collaboration in managing global health emergencies.

Targeting Resources and Policy Development

Beyond scientific research, the list serves as a tool for policymakers and public health officials. By identifying high-priority pathogens, governments can allocate resources more effectively and develop targeted policies to mitigate risks. For example, including bacterial threats like cholera and plague draws attention to the need for improved sanitation and access to clean water in vulnerable regions.

The WHO’s approach also encourages investment in infrastructure, such as laboratories and health systems, to better prepare for future outbreaks. By addressing systemic weaknesses, countries can enhance their resilience to both existing and emerging threats.

A Call to Action

The updated priority pathogen list is a reminder that vigilance and preparedness are essential to safeguarding global health. It highlights the urgent need for continued research, robust surveillance systems, and international collaboration to prevent future pandemics. While the challenges are significant, the list also offers hope—by focusing on these high-risk pathogens, the global community can take proactive steps to mitigate risks and save lives.

My Personal RX on Pandemic Preparedness

As a doctor, I’ve seen firsthand how critical it is to stay prepared in the face of potential health threats. While global health organizations focus on large-scale strategies, there’s a lot individuals can do to protect themselves and their communities. Here’s my practical guide to staying resilient and prepared, combining simple habits and holistic health tools to bolster your defense against emerging threats:

1. Stay Vaccinated: Ensure you’re up-to-date on all recommended vaccines, including those for influenza and other preventable diseases. Vaccines are one of the most effective tools to reduce your risk of severe illness.
2. Boost Your Immune Reserves: Incorporate an immune support regimen into your daily routine. A targeted blend of nutrients can strengthen your body’s defenses, giving you broad-spectrum protection against illnesses.
3. Practice Consistent Hygiene: Wash your hands frequently, especially before eating or touching your face. This simple habit can significantly reduce the spread of viruses and bacteria.
4. Maintain a Healthy Diet: Focus on nutrient-dense foods like fruits, vegetables, whole grains, and lean proteins to keep your body in optimal condition to fight infections.
5. Build a Pandemic Kit: Have essentials like masks, hand sanitizers, and basic medications at home. Being prepared reduces stress and ensures quick action in emergencies.
6. Holistic Health Planning: Invest in a comprehensive guide like <Protocolguide to align your lifestyle with your health goals. It’s a powerful resource for creating habits that protect your body and mind.
7. Exercise Regularly: Regular physical activity enhances circulation and boosts immune function. Aim for at least 150 minutes of moderate exercise weekly.
8. Stay Informed: Follow updates from trusted sources like WHO and your local health department. Knowledge is a key part of preparedness.
9. Focus on Mental Health: Stress can weaken your immune system, so prioritize activities like meditation, journaling, or spending time in nature to manage anxiety.
10. Prioritize Sleep: Aim for 7-9 hours of quality sleep each night. Rest is vital for repairing the body and maintaining a robust immune response.

These steps not only prepare you for potential pandemics but also help create a foundation for overall health and wellness. Prevention and resilience go hand in hand!

Sources:

1. World Health Organization. (2024, March 21). World Health Organization on LinkedIn: How are scientists working to prevent the next pandemic? What do countries. . . [Video]. https://www.linkedin.com/posts/world-health-organization_how-are-scientists-working-to-prevent-the-activity-7176501577401204736-QX77
2. The next pandemic: not if, but when. (2024, September 12). News. https://www.hsph.harvard.edu/news/features/next-pandemic-not-if-but-when/