Is there a vaccine in the form of a patch against Disease X? No, that's not true: Disease X is not a known disease. It is the name given by scientists and the World Health Organization to a hypothetical disease caused by an unknown pathogen that could potentially emerge in the future and cause a serious international epidemic or pandemic. Therefore, there is no vaccine against it.
The claim appeared in a TikTok video (archived here) published on January 18, 2024, with a caption translated into English from Croatian by Lead Stories staff that reads:
They already know what it will be like, and they already have the vaccine in patches
This is what the post looked like on TikTok at the time of writing:
(Source: TikTok screenshot taken on Mon Feb 12 09:14:26 2024 UTC)
Disease X is not a disease caused by a specific virus, but it is a designation by the World Health Organization which added it to a list of pathogens considered a priority for research in 2017 (archived here). The World Health Organization (archived here) stated:
Disease X is included to indicate an unknown pathogen that could cause a serious international epidemic. The experts will recommend a list of priority pathogens that need further research and investment. The process will include both scientific and public health criteria, as well as criteria related to socioeconomic impact, access, and equity. The current list includes COVID-19, Crimean-Cong haemorrhagic fever, Ebola virus disease and Marburg virus disease, Lassa fever, Middle East respiratory syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS), Nipah and henipaviral diseases, Rift Valley fever, Zika and Disease X.
To prepare for an outbreak of a so-called Disease X pathogen, the Coalition for Epidemic Preparedness Innovations (CEPI) and the University of Oxford partnered (archived here) in August 2023, to work on safe, effective, and globally accessible vaccines. The coalition committed up to 80 million USD to work on a range of vaccine prototypes to use against viruses that risk causing the next large-scale pandemic disease and hopes to streamline the development of future vaccine candidates potentially within 100 days of identifying a disease.
Another team of more than 200 scientists at the government's high-security Vaccine Development and Evaluation Centre (archived here) at Porton Down laboratory complex in Wiltshire, UK, has also begun developing vaccines (archived here) to protect against potentially threatening pathogens. They have developed tests through which they can measure the effectiveness of vaccines against bacterial and viral infections and are evaluating how to combat more threatening pathogens with pandemic potential, including avian influenza, Mpox, and Crimean-Congo haemorrhagic fever.
However, none of the vaccines that are currently being investigated for future development are yet designed to vaccinate against an as-yet-unknown disease, commonly referred to as Disease X.
Additional Lead Stories fact checks of claims about Disease X can be read here.