Fact Check: Measles outbreaks not linked to ‘Disease X’ pandemic planning

Outbreaks of measles virus in the UK and U.S. are not related to hypothetical “Disease X” - a placeholder term for an unknown future pandemic-causing pathogen - as suggested by misleading social media posts.

While measles is highly contagious among people who are not vaccinated - such as groups linked to recent outbreaks – it is also highly preventable with the existing vaccine and therefore has little pandemic potential, experts told Reuters.

The UK Health Security Agency (UKHSA) declared a national health incident on Jan. 19, 2024, after more than 200 measles cases were confirmed among children in the West Midlands since Oct. 1, 2023. Clusters of measles cases in parts of the U.S. were also reported to

, opens new tab the U.S. Centers for Disease Control and Prevention (CDC) in late 2023 and early 2024.

Accounts on social media platform X

, opens new tab, Instagram, opens new tab and Facebook, opens new tab falsely linked the measles cases to Disease X and to the 2024 U.S. elections.