Review Artcle Journal of Communicable Diseases (P-ISSN: 0019-5138 & E-ISSN: 2581-351X) Copyright (c) 2021: Author(s). Published by Advanced Research Publicatons Journal of Communicable Diseases Volume 53, Issue 4 - 2021, Pg. No. 135-139 Peer Reviewed & Open Access Journal Corresponding Author: Shakya Sinha, Postgraduate Department of Zoology, Asutosh College (University of Calcuta), West Bengal, India. E-mail Id: shakyasinha24@gmail.com Orcid Id: htps://orcid.org/0000-0003-4758-1693 How to cite this artcle: Tilak R, Bhatacharya S, Tilak VW, Sinha S. Disease X: Exploring the Unexplored, Knowable Unknown. J Commun Dis. 2021;53(4):135-139. Date of Submission: 2021-12-02 Date of Acceptance: 2021-12-23 I N F O A B S T R A C T The glaring uncertainty regarding the identty of certain pathogenic bio-agents having potental for a severe global public health security threat has spurned the internatonal health agencies to classify it as Disease X, which has been added to the “blueprint priority diseases” as a placeholder name for a “knowable unknown” pathogen by the WHO. The zoonotc diseases of viral origin and the synthetc viruses are acknowledged as the most likely agents of Disease X causing public health emergencies of internatonal concern in tmes to come. The challenges in the rapid containment of Disease X pandemics could be the inability for early detecton of the infectous agents, presence of a large immunologically naïve populaton, lack of knowledge of clinical spectrum, no pathogen-specifc efectve drugs and/ or vaccines and sudden surge of patents requiring hospitalisaton which collectvely compromise the public health system especially in resource stricken countries and leads to its eventual collapse. Well-equipped feld laboratories, sentnel surveillance centres for viruses and other microbial pathogens are needed in strategically important and sensitve areas of concern for monitoring for early detecton of possible bio-agents of Disease X, if any. In a changing geo-socio politcal scenario, use of the synthetc viruses as a potental bio-weapon for mass destructon and/ or for the economic breakdown of a targeted country should not be ruled out. Thus, capacity building, global technical collaboraton and stringent internatonal regulatons to prevent the development of bio- weapons are also obligatory to prevent any possible future pandemics of Disease X. Keywords: Disease X, Pandemics, Surveillance, Bio-weapons, Blueprint Priority Diseases Disease X: Exploring the Unexplored, Knowable Unknown Rina Tilak 1 , Sajal Bhatacharya 2 , VW Tilak 3 , Shakya Sinha 4 1 Scientst ‘G’, 3 Ex Dean, Armed Forces Medical College, Pune, India. 2 Professor (Associate), 4 Research Scholar, Postgraduate Department of Zoology, Asutosh College (University of Calcuta), Kolkata, West Bengal, India. DOI: htps://doi.org/10.24321/0019.5138.202183 Introduction The world today is more crowded, more polluted, less stable ecologically but more vulnerable to diseases and disruptons. 1 The world is perched on a tcking tme bomb holding a vast number of undiscovered, potentally deadly disease-causing pathogens that await opportunites to unleash unprecedented havoc at the slightest provocaton by man. With each passing day, the world waits with bated breath the reportng of the frst patent of the dreaded ‘Disease X’, an insidious unknown threat.