1. What is ‘Disease X?’
It’s the somewhat mysterious name for an illness caused by a presently unknown, yet serious microbial threat. The World Health Organization added Disease X in 2017 to a short list of pathogens deemed a top priority for research, alongside known killers like Severe Acute Respiratory Syndrome (SARS) and Ebola. Covid-19, caused by a novel coronavirus, was an example of a Disease X when it touched off the pandemic at the end of 2019. The vast reservoir of viruses circulating in wildlife are seen as a likely source of more such diseases. That’s because of their potential to spill over and infect other species, including humans, giving rise to an infection against which people will have no immunity.
2. What’s the point of studying Disease X?
As the WHO puts it, it’s to “enable early cross-cutting R&D preparedness that is also relevant” for an unknown disease. The humanitarian crisis sparked by the 2014–2016 Ebola epidemic in West Africa was a wake up call. Despite decades of research, there were no products ready to deploy in time to save more than 11,000 lives. In response, the WHO created an R&D Blueprint to accelerate development of a range of tools for “priority diseases.” The current list includes:
• Covid-19,
• Crimean-Congo hemorrhagic fever,
• Ebola virus disease and Marburg virus disease,
• Lassa fever,
• Middle East respiratory syndrome (MERS) and SARS,
• Nipah and henipaviral diseases,
• Rift Valley fever,
• Zika
