Disease X - Introduction to Disease X - 13/Jan/2024

Disease X – Introduction to Disease X – 13/Jan/2024

Introduction to Disease X

In recent years, a term has emerged in international public health spheres which, while it does not describe a specific disease, represents a deeply significant concept: “Disease X”. Coined by the World Health Organization (WHO), the term denotes the knowledge that a future international pandemic could be caused by an unknown pathogen that hasn’t yet entered into the human population. This term carries substantial weight as it highlights the unpredictability of potential future global health risks and the importance of adaptability and comprehensive preparation within the international healthcare community.

Origins of the Term “Disease X”

The term “Disease X” was first used in the WHO’s 2018 annual review of their Blueprint list of priority diseases. The Blueprint list was formulated to increase focus on, and funds for, research into diseases that pose major public health risks due to their epidemic potential and for which there are insufficient countermeasures. The diseases on this list are typically severe, rapidly spreading, and of significant concern to public health. They include Ebola, SARS, and Zika among others.

“Disease X” was added to this list as a sort of placeholder, denoting a theoretical disease that could cause a serious international epidemic. The purpose of including “Disease X” in the list was to ensure that the health research infrastructure would be flexible and prepared for all types of outbreaks, not only those caused by known diseases.

Potential Origins of Disease X

While “Disease X” implies an unknown disease, it does not necessarily mean that the pathogen causing the disease would be completely new or unidentified. Instead, Disease X could arise from a known pathogen that morphs into a new disease due to changes in its environment or in host populations.

For example, many major disease outbreaks in recent history have originated from viruses that have jumped from animal populations to humans. This includes diseases like HIV, the flu, and most recently, the coronavirus (COVID-19). Increasing human contact with wildlife, driven in part by deforestation and climate change, has increased the likelihood of such zoonotic transfers.

In addition, Disease X could also represent an intentionally created pathogen. Bioterrorism, though a less pleasant scenario to imagine, is always a potential source of new pandemics. The rapid advancements in genetic engineering mean that the potential for the creation of new, artificially-introduced diseases is unfortunately present.

Preparation for Disease X

Given the unknown nature of Disease X, preparation is necessarily broad and multi-faceted, and involves strengthening of healthcare systems as well as investment in research to understand how new diseases emerge and spread in human populations.

On the healthcare side, preparations can include increasing capacity in hospitals, training healthcare workers to deal with new diseases, and strengthening the supply chain for essential medical supplies. Moreover, a vital component of preparation involves improving surveillance systems to quickly detect and respond to new disease outbreaks when they occur.

On the research side, efforts are often made to understand how environmental changes may affect disease emergence and spread. This can include monitoring wildlife for potential new diseases, investigating how changes in land use and climate can affect disease spread, and studying how social and demographic changes can affect disease epidemiology.

With regard to technological advancements, the development of platform technologies that can be adapted rapidly to new diseases is seen as a key preparation method. For example, the technology used to create the new COVID-19 vaccines – mRNA vaccines – is viewed as a sort of platform technology that can be adapted for use against other viruses.


  • Disease X is a hypothetical future disease that could cause a major global epidemic.
  • The term “Disease X” was coined by the WHO in 2018 and added to their list of priority diseases.
  • Disease X could be caused by a known pathogen that changes to form a new disease, a pathogen crossing over from wildlife to humans, or even an artificially-created pathogen from bioengineering or bioterrorism.
  • Preparation for Disease X can involve strengthening healthcare systems, performing research on potential disease jump points, and utilizing technological advancements in vaccines and surveillance.
  • Image Description

    The image accompanying the article is a striking graphic representation of Disease X. In the center, a large black “X” is superimposed on a biohazard symbol set against a grid of global connections, suggesting the rapid spread of diseases. To the side, images of microscopic pathogens and the silhouette of a bat allude to the potential origins of a future Disease X.