What is Disease X?

By R.J.

Since 2015 the World Health Organisation has released an annual list of up to 10 “blueprint priority diseases” requiring immediate attention based on their epidemic potential or lack of sufficient countermeasures. The list has consistently contained now-well-known deadly viruses such as Ebola, Zika and SARS, as well as less-known diseases such as Lassa fever and Marburg virus disease. The difference this year is that included among the regulars is something called Disease X. What exactly is this mysterious disease and why has it been included?

The WHO’s selection, known as the 2018 R&D Blueprint, was started as a response to the Ebola crisis in 2014, which has since infected nearly 29,000 people and killed more than 11,000. The list serves as a warning to governments that research and development needs to be an integral part of the response to epidemics. No one was ready for Ebola when it hit West Africa at that time. 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.” Experts now recognise that moving fast to find a vaccine involves creating so-called “platform technologies” in advance. These involve scientists developing recipes for vaccines that can be customised. When an outbreak happens, scientists can sequence the unique genetics of the particular virus and enter the correct sequence into the platform to create a new vaccine. In the case of Ebola, this meant an effective vaccine could be developed and tested in 12 months rather than the usual 5-10 years.