A pandemic tabletop exercise at the Grand Challenges Annual Meeting in Brussels simulating a novel pathogen with a higher fatality rate than COVID-19 that disproportionately affects children and young people — the “Event 201 sequel” designed to stress-test whether post-COVID lessons were actually learned.
Open Intelligence Dossier Back to HubPrimary intelligence from the Catastrophic Contagion tabletop exercise — the first major pandemic simulation conducted after COVID-19, and the fifth in the Johns Hopkins exercise family that began with Dark Winter in 2001.
The fictional pathogen, “Severe Epidemic Enterovirus Respiratory Syndrome” (SEERS), had a higher fatality rate than COVID-19 and disproportionately affected children and young people. Participants grappled with whether countries should take different, stronger, earlier measures when a pathogen selectively kills children — a scenario designed to be emotionally and politically devastating.
Even a group of the world’s most experienced public health leaders — who had personally lived through COVID-19 — wrestled with opposing views on whether to impose travel restrictions or close schools. The exercise proved that pandemic wisdom is not cumulative: each new pathogen with unique characteristics resets the debate and forces impossible trade-offs under uncertainty.
Unlike Event 201 (dominated by Western participants), Catastrophic Contagion deliberately centered leaders from Africa and the Global South — including current and former Health Ministers from Senegal, Rwanda, Nigeria, Angola, and Liberia — reflecting that the next pandemic is most likely to begin in regions with fragile health systems and limited surveillance capacity.
Bill Gates participated directly, making this the third major pandemic exercise he was involved in (after Event 201 in 2019 and foundation-supported simulations). His presence underscored the foundation’s ongoing strategic focus on pandemic preparedness as a core philanthropic priority — and drew renewed conspiracy theory attention.
Countries need to collaborate to anticipate misinformation threats and prepare to combat them with their own laws and procedures. Just as economic harms can be anticipated in pandemic plans, so too can predictable false health messaging. The exercise found that the WHO alone cannot stop the spread of mis- and disinformation.
Despite COVAX during COVID-19, public health leaders still lacked confidence in fair allocation mechanisms. The exercise proved that empowering regions with poor infrastructure requires building manufacturing and distribution capacities now — not during a pandemic when rich nations will inevitably hoard supplies, regardless of pledges.
Simulated a series of WHO Emergency Health Advisory Board meetings as SEERS spread from a regional epidemic to a global pandemic affecting millions of children.
An epidemic begins in a developing region, caused by SEERS (Severe Epidemic Enterovirus Respiratory Syndrome). Initial cases show unusually high mortality among children and young adults. Local health systems are quickly overwhelmed. International attention is slow to mobilize — echoing the early days of Ebola 2014.
The epidemic spreads internationally, becoming a pandemic. The virus proves more lethal than COVID-19. Travel restrictions debate intensifies. School closures become politically explosive as the pathogen preferentially kills children. Parents demand action; economic interests resist.
Leaders must make urgent decisions with incomplete data: shut borders or keep them open? Close schools permanently or accept pediatric deaths? Divert resources from COVID recovery to a new threat? Equity vs. speed in vaccine distribution. Misinformation explodes on social media, undermining public health messaging.
The exercise concluded with four strategic lessons: (1) leaders must prepare now for bold early-stage decisions; (2) establish a global professional network of public health leaders; (3) prioritize trust-building and counter-misinformation capacity; (4) strengthen international systems for allocating scarce medical resources.
10 current and former Health Ministers and senior public health officials from across the world — deliberately weighted toward the Global South.
The exercise produced four major lessons for future pandemic preparedness — all of which echo warnings from previous JHU exercises.
In the early days of a major new epidemic, there could be a brief window to stop it becoming a pandemic. Decisive and bold action would need to be taken in the face of incomplete data, high scientific uncertainty, and potential political resistance. Thinking through these challenges must start now.
Establish a “Pandemic Corps” — a worldwide professionalized network of public health leaders who can work together between epidemics to improve preparedness and provide mutual aid during outbreaks. Political leaders need consensus views from trusted experts.
In future pandemics, expect even more major disruptions from misinformation. Countries need to collaborate to anticipate that threat and prepare with their own laws and procedures. Predictable false health messaging can be anticipated and countered pre-emptively — just as economic harms can be modeled in advance.
Build manufacturing, distribution, and administration capacities worldwide — especially in countries with poor infrastructure. Even with a global commitment to equity, implementing equitable allocation is extremely difficult, especially with cold-chain requirements or IV administration.
Catastrophic Contagion is the fifth major tabletop exercise from the Johns Hopkins Center for Health Security — a two-decade lineage of pandemic warnings.
| Exercise | Date | Pathogen | Key Difference |
|---|---|---|---|
| Dark Winter | June 2001 | Smallpox | U.S. domestic bioterror response |
| Atlantic Storm | Jan 2005 | Smallpox | International coordination failure |
| Clade X | May 2018 | Engineered parainfluenza/Nipah | Catastrophic pandemic (900M dead) |
| Event 201 | Oct 2019 | Novel Coronavirus | Public-private response (65M dead) |
| Catastrophic Contagion | Oct 2022 | Novel Enterovirus (SEERS) | Post-COVID; children disproportionately affected |
Even after living through COVID-19, the world’s most experienced health leaders could not agree on basic containment measures. The exercise proved that pandemic lessons are not automatically retained — each new pathogen with unique characteristics (especially one killing children) resets political calculations and forces impossible trade-offs. COVID-19 taught us many lessons. This exercise showed we haven’t learned them.
Like Event 201 before it, Catastrophic Contagion became a target for conspiracy theories — the very problem it was designed to study.
Within weeks of the exercise becoming public, conspiracy theorists claimed it was “predictive programming” for a planned pandemic targeting children. Multiple fact-checking organizations (Reuters, USA Today, PolitiFact) debunked these claims. The exercise was a standard preparedness simulation, not a prophecy — mirroring the exact pattern seen after Event 201.
Just as Event 201 (October 2019) was falsely claimed to have “predicted” COVID-19, Catastrophic Contagion faced identical accusations. The JHU Center for Health Security has repeatedly stated that these exercises identify known vulnerabilities, not predict specific future events.
Unlike Event 201 (which was livestreamed with extensive documentation), Catastrophic Contagion was conducted behind closed doors with limited public materials released. Some public health transparency advocates argued this approach, while protecting frank discussion, contributed to the very distrust the exercise warned about.
1. Johns Hopkins Center for Health Security, “Catastrophic Contagion,” October 2022. centerforhealthsecurity.org
2. Reuters Fact Check, “Catastrophic Contagion video is fictional,” December 15, 2022.
3. USA Today Fact Check, “Catastrophic Contagion tested pandemic preparedness,” January 13, 2023.
4. PolitiFact, “Simulation was not prep for a planned 2025 pandemic,” May 5, 2023.
5. Bill & Melinda Gates Foundation, Grand Challenges Annual Meeting, Brussels 2022.
6. World Health Organization, Emergency Health Advisory Board framework documents.
7. JHU CHS, “Lessons from the Exercise,” published report, 2022.
8. Science Feedback, “Simulation exercises are a normal part of pandemic preparedness,” 2023.