CLADE X – Pandemic Simulation Event – May 15th 2018

Prior to EVENT 201, there was a somewhat lesser known Pandemic Simulation event held on 15th May 2018 at the Mandarin Oriental Hotel in Washington, DC called CLADE X. This one day event is introduced as “The Johns Hopkins Health Security Exercise CLADE X” and thus appears to have been organised by and / or associated with The Johns Hopkins Bloomberg School of Public Health as it appears on the Center for Health Security website.  

31st May 2020

From the CLADE X website at


Clade X is a day-long pandemic tabletop exercise that simulated a series of National Security Council–convened meetings of 10 US government leaders, played by individuals prominent in the fields of national security or epidemic response.

Drawing from actual events, Clade X identified important policy issues and preparedness challenges that could be solved with sufficient political will and attention. These issues were designed in a narrative to engage and educate the participants and the audience.

Lessons learned were distilled and shared broadly following the exercise.


Faced with a rapidly evolving biological threat landscape, government leaders in the United States and abroad are eager to identify long-term policy commitments that will strengthen preparedness and mitigate risk. Clade X illustrated high-level strategic decisions and policies needed to prevent a severe pandemic or diminish its consequences should prevention fail.

Similar to findings from the Center’s two previous exercises, Dark Winter and Atlantic Storm, key takeaways from Clade X will educate senior leaders at the highest level of the US government, as well as members of the global policy and preparedness community and the general public. This is distinct from many other forms of tabletop exercises that test protocols or technical policies of a specific organization.

In addition, exercises like Clade X are a particularly effective way to help policymakers gain a fuller understanding of the urgent challenges they could face in a dynamic, real-world crisis.