Disease X-- as the World Health Organisation (WHO) calls it-- might lead to another pandemic deadlier than the COVID pandemic we all have been dealing with since 2020.
"Disease X represents the knowledge that a serious international epidemic could be caused by a pathogen currently unknown to cause human disease. The R&D Blueprint explicitly seeks to enable early cross-cutting R&D preparedness that is also relevant for an unknown “Disease X”," as the WHO defines it.