Disease X

SEM of SARS-CoV-2, speculated in 2020 as being the first real-world virus to create Disease X.[1][2][3]

Disease X is a placeholder name that was adopted by the World Health Organization (WHO) in February 2018 on their shortlist list of blueprint priority diseases to represent a hypothetical, unknown pathogen that could cause a future epidemic.[4][5] The rationale was to ensure that WHO planning was sufficiently flexible to adapt to an unknown pathogen.[6][4] Experts noted that the concept of Disease X would encourage WHO projects to focus their research efforts on entire classes of various viruses (e.g. flaviviruses), instead of just individual strains (e.g. zika virus), so as to improve WHO capability to respond to unforeseen strains.[7] In 2020, it was speculated, including among WHO expert advisors, that the coronavirus disease (from the SARS-CoV-2 virus strain) met the requirements to be first Disease X.[1][2][3]


Sir Jeremy Farrar, Chair of the WHO R&D Blueprint Scientific Advisory Group.[8]

In May 2015, the WHO was asked by member organizations to create an "R&D Blueprint for Action to Prevent Epidemics" to generate ideas that would reduce the time lag between the identification of viral outbreaks and the approval of vaccines/treatments, to stop the outbreaks turning into a "public health emergency".[9][4] The focus was to be on the most serious emerging infectious diseases (EIDs) for which few preventive options were available.[9][10] A group of global experts, the "R&D Blueprint Scientific Advisory Group",[11] was assembled by the WHO to draft a shortlist of less than ten "blueprint priority diseases".[5][4][9]

Since 2015, the shortlist of less than 10 EIDs has been updated annually and has consistently included widely known names such as Ebola, Zika and SARS (e.g. cause of large-scale infections), and more geographically specific names such as Lassa fever, Marburg virus, Rift Valley fever, and Nipah virus.[5][10]

In February 2018, after the "2018 R&D Blueprint" meeting in Geneva, the WHO added Disease X to the shortlist as a placeholder for a "knowable unknown" pathogen.[12][6][4] The Disease X placeholder acknowledged the potential for a future epidemic that could be caused by an unknown pathogen, and to ensure WHO's planning and capabilities were flexible enough to adapt to such an event.[5][13][14]

At the announcement, the WHO said "Disease X represents the knowledge that a serious international epidemic could be caused by a pathogen currently unknown to cause human disease".[15][6][5] John-Arne Røttingen, of the R&D Blueprint Special Advisory Group,[8] said: "History tells us that it is likely the next big outbreak will be something we have not seen before", and "It may seem strange to be adding an 'X' but the point is to make sure we prepare and plan flexibly in terms of vaccines and diagnostic tests. We want to see 'plug and play' platforms developed which will work for any, or a wide number of diseases; systems that will allow us to create countermeasures at speed".[6][10] US expert Anthony Fauci said "WHO recognizes it must "nimbly move" and this involves creating platform technologies", and that to develop such platforms, WHO would have to research entire classes of viruses, highlighting flaviviruses and saying: "If you develop an understanding of the commonalities of those, you can respond more rapidly".[7]


The adoption of Disease X was welcomed, and Dr. Richard Hatchett of the Coalition for Epidemic Preparedness Innovations (CEPI), wrote "It might sound like science fiction, but Disease X is something we must prepare for", noting that despite the success in controlling the 2014 Western African Ebola virus epidemic, strains of the disease had returned in 2018.[16] In February 2019, CEPI announced funding of US$34 million to the German-based CureVac biopharmaceutical company to develop an "RNA Printer prototype", that CEPI said could, "..prepare for rapid response to unknown pathogens (i.e., Disease X)".[17]

Parallels were drawn with the efforts by the United States Agency for International Development (USAID) and their PREDICT programme, which was designed to act as an early warning pandemic system, by sourcing and researching animal viruses in particular "hot spots" of animal-human interaction.[18]

In September 2019, the Daily Telegraph reported on how Public Health England (PHE) had launched its own investigation for a potential Disease X in the United Kingdom from the diverse range of diseases reported in their health system; they noted that 12 novel diseases and/or viruses had been recorded by PHE in the last decade.[19]

In October 2019 in New York, the WHO's Health Emergencies Programme ran a "Disease X dummy run" to simulate a global pandemic by a Disease X, in order for its 150 participants from various world health agencies and public health systems to better prepare and share ideas and observations for combatting such an eventuality.[20][21]

In March 2020, The Lancet published a paper titled "Disease X: accelerating the development of medical countermeasures for the next pandemic", which expanded the term to include Pathogen X (the pathogen that leads to Disease X), and identified areas of product development and international coordination that would help in combatting any future Disease X.[22]


Zoonotic virusesEdit

On the addition of Disease X in 2018, the WHO said it could come from many sources citing haemorrhagic fevers and the more recent non-polio enterovirus.[6] However, Røttingen speculated that Disease X would be more likely come from zoonotic transmission (an animal virus that jumps to humans), saying: "It's a natural process and it is vital that we are aware and prepare. It is probably the greatest risk".[6][10] WHO special advisor Professor Marion Koopmans, also noted that the rate at which zoonotic diseases were appearing was accelerating, saying: "The intensity of animal and human contact is becoming much greater as the world develops. This makes it more likely new diseases will emerge but also modern travel and trade make it much more likely they will spread".[10][23]

H7N9 (2018)Edit

In 2018, a new strain of the H7N9 "bird flu" virus, with a 38 percent mortality rate, was likened to a potential Disease X by some international health authorities (but not the WHO, or the R&D Blueprint group).[24][25] China would not share samples of the new H7N9 strain, however, they eventually brought the outbreak under control and the urgency dissipated.[26]

COVID-19 (2019–2020)Edit

Marion Koopmans, WHO R&D Blueprint Special Advisory Group.[8]

From the outset of the 2019–20 coronavirus pandemic, experts have speculated whether COVID-19 met the criteria to be Disease X.[27][28] In early February 2020, Chinese virologist Shi Zhengli from the Wuhan Institute of Virology, wrote that the first Disease X is from a coronavirus.[3] Later that month, Marion Koopmans [nl], Head of Viroscience at Erasmus University Medical Center in Rotterdam, and a member of the WHO's R&D Blueprint Special Advisory Group,[8][29] wrote in scientific journal Cell, "Whether it will be contained or not, this outbreak is rapidly becoming the first true pandemic challenge that fits the disease X category".[2][30][31] At the same time, Peter Daszak, also a member of the WHO's R&D Blueprint, wrote in an opinion piece in the New York Times saying: "In a nutshell, Covid-19 is Disease X".[1]

Synthetic virusesEdit

In 2018, WHO R&D Blueprint Special Advisor Group member Røttingen was questioned about the potential of Disease X to come from the ability of gene editing technology to produce synthetic viruses (e.g. the 2017 synthesis of Orthopoxvirus in Canada was cited), which could be released through an accident or even an act of terror. Røttingen felt it was less likely but cautioned: "Synthetic biology allows for the creation of deadly new viruses. It is also the case that where you have a new disease there is no resistance in the population and that means it can spread fast".[10]

Bacterial infectionEdit

In September 2019, Public Health England (PHE) reported that the increasing antibiotic resistance of bacteria, even to "last-resort" antibiotics such as carbapenems and colistin, could also turn into a potential Disease X; citing the antibiotic resistance in gonorrhea as an example.[32]

In popular cultureEdit

In 2018, the Museum of London ran an exhibition titled "Disease X: London's next epidemic?", hosted for the centenary of the Spanish flu epidemic from 1918.[33][34]

The term features in the title of several fiction books that involve global pandemic diseases.[35][36]

See alsoEdit


  1. ^ a b c Daszak, Peter (22 February 2020). "We Knew Disease X Was Coming. It's Here Now". The New York Times. Retrieved 8 March 2020.
  2. ^ a b c Gale, Jason (22 February 2020). "Coronavirus May Be 'Disease X' Health Experts Warned About". Bloomberg News. Retrieved 8 March 2020.
  3. ^ a b c Shi Zhengli; Jiang Shibo (2020). "The First Disease X is Caused by a Highly Transmissible Acute Respiratory Syndrome Coronavirus". Virologica Sinica. doi:10.1007/s12250-020-00206-5. PMID 32060789.
  4. ^ a b c d e "List of Blueprint priority diseases". World Health Organization. 7 February 2018. Retrieved 20 March 2020.
  5. ^ a b c d e Editorial (13 March 2018). "What is Disease X?". Economist. Retrieved 20 March 2020. By listing Disease X, an undetermined disease, the WHO is acknowledging that outbreaks do not always come from an identified source and that, as it admits, "a serious international epidemic could be caused by a pathogen currently unknown to cause human disease."
  6. ^ a b c d e f Barns, Tom (11 March 2018). "World Health Organisation fears new 'Disease X' could cause a global pandemic". The Independent. Retrieved 20 March 2020.
  7. ^ a b Scutti, Susan (12 March 2018). "World Health Organization gets ready for 'Disease X'". CNN News. Retrieved 20 March 2020.
  8. ^ a b c d "R&D Blueprint - Scientific Advisory Group members". World Health Organization. Retrieved 21 March 2020.
  9. ^ a b c World Health Organization (6–7 February 2018). 2018 Annual review of diseases prioritized under the Research and Development Blueprint (PDF) (Report). Geneva, Switzerland. p. 17. Retrieved 20 March 2020.
  10. ^ a b c d e f Nuki, Paul; Shaikh, Alanna (10 March 2018). "Scientists put on alert for deadly new pathogen – 'Disease X'". Daily Telegraph. Retrieved 20 March 2018.
  11. ^ "R&D Blueprint". World Health Organization. Retrieved 21 March 2020.
  12. ^ Shaikh, Alanna; Nuki, Paul (2019-07-22). "What is 'Disease X', the mystery killer keeping scientists awake?". The Telegraph. ISSN 0307-1235. Retrieved 2020-01-18.
  13. ^ Lee, Bruce Y. (March 10, 2018). "Disease X is what may Become the Biggest Infectious Threat to our World". Forbes. Retrieved March 11, 2018.
  14. ^ "WHO | List of Blueprint priority diseases". WHO. Retrieved 2020-01-18.
  15. ^ Andreas Whittam Smith (11 March 2018). "One hundred years on from the Spanish Flu, we are facing another major pandemic". The Independent. Retrieved 20 March 2020.
  16. ^ Hatchett, Richard (15 May 2018). "It might sound like science fiction, but Disease X is something we must prepare for". Daily Telegraph. Retrieved 20 March 2020.
  17. ^ Dimitrios Gouglas; Mario Christodoulou; Stanley A Plotkin; Richard Hatchett (November 2019). "CEPI: Driving Progress Towards Epidemic Preparedness And Response". Epidemiologic Reviews. doi:10.1093/epirev/mxz012. PMID 31673694.
  18. ^ Shute, Joe (September 2019). "Virus hunters: Meet the scientists searching for Disease X". Daily Telegraph. Retrieved 20 March 2020.
  19. ^ Gulland, Anne (11 September 2019). "Revealed: Public Health England 'hot on the trail' of Disease X". Daily Telegraph. Retrieved 20 March 2020.
  20. ^ Alexander, Harriet (21 October 2019). "Disease X dummy run: World health experts prepare for a deadly pandemic and its fallout". Daily Telegraph. Retrieved 20 March 2020.
  21. ^ James Hamblin (28 March 2020). "The Curve Is Not Flat Enough". The Atlantic. Retrieved 28 March 2020.
  22. ^ Simpson, Shmona; Michael C Kaufmann; Glozman, Vitaly; Chakrabarti, Ajoy (March 2020). "Disease X: accelerating the development of medical countermeasures for the next pandemic". The Lancet. doi:10.1016/S1473-3099(20)30123-7. PMID 32197097.
  23. ^ Cousins, Sophie (2018-05-10). "WHO hedges its bets: the next global pandemic could be disease X". BMJ. 361: k2015. doi:10.1136/bmj.k2015. ISSN 0959-8138. PMID 29748222.
  24. ^ Gulland, Anne (15 June 2018). "Deadly Chinese poultry flu could be 'disease X' that sparks worldwide pandemic". Daily Telegraph. Retrieved 20 March 2020.
  25. ^ Andrew, Scottie (15 June 2018). "WHAT IS DISEASE X? DEADLY BIRD FLU VIRUS COULD BE NEXT PANDEMIC". Newsweek. Retrieved 20 March 2020.
  26. ^ Majid, Aisha (29 August 2019). "Disease X: China ignores UK request to share samples of flu virus with pandemic potential". Daily Telegraph. Retrieved 20 March 2010.
  27. ^ Gulland, Anne (2020-01-09). "Have Chinese researchers uncovered the new disease X?". The Telegraph. ISSN 0307-1235. Retrieved 2020-01-18.
  28. ^ Robin McKie (6 February 2020). "Coronavirus: the huge unknowns". The Guardian. Retrieved 21 March 2020. This hope now looks forlorn with the sudden emergence of the respiratory disease Covid-19, which has rapidly acquired most of the characteristic of a Disease X.
  29. ^ "R&D Blueprint: Marion Koopmans (Biography)". World Health Organization. Retrieved 20 March 2020.
  30. ^ Mercer, David (25 February 2020). "Coronavirus outbreak could be feared 'Disease X', says World Health Organisation adviser". Sky News. Retrieved 8 March 2020.
  31. ^ Aaro, David (27 February 2020). "What is Disease X?". Fox News. Retrieved 8 March 2020.
  32. ^ Campbell, Denis (11 September 2019). "Bacteria developing new ways to resist antibiotics, doctors warn". The Guardian. Retrieved 20 March 2020.
  33. ^ Addley, Esther (November 2018). "Queen Victoria's mourning dress among items in Disease X exhibition". The Guardian. Retrieved 20 March 2020.
  34. ^ "Disease X: London's next epidemic?". Museum of London. Retrieved 20 March 2020.
  35. ^ N. J. Croft (January 2020). Disease X. Sideways Books. ASIN B081XS6FN7.
  36. ^ Burdette, Shannon C. (October 2019). DISEASE X: THE OUTBREAK. ISBN 978-1703667806.

External linksEdit