Mpox in Sierra Leone and the Mano River Union: an epidemic unfolding in real time

The 2025 mpox outbreak in Sierra Leone represents an unprecedented public health crisis, escalating rapidly from minimal prior cases to over 4400 confirmed infections within 6 months. This surge challenges previous assumptions about mpox epidemiology in West Africa and highlights critical vulnerabilities in disease surveillance, diagnostics and health system preparedness-challenges shared across the Mano River Union (MRU) region, including Liberia, Guinea and Côte d'Ivoire. Despite global commitments to equitable vaccine access, Sierra Leone and its neighbours have faced significant delays and fragmented mpox vaccine deployment, reflecting systemic failures in global health financing, vaccine ecosystems and governance. In this analysis, we examine the demographic and geographic features of the outbreak within Sierra Leone and the MRU, operational challenges and the urgent need for a coordinated equity-driven regional response. In doing so, we call for targeted vaccination, decentralised testing, the integration of mpox control into sexual health programmes and the strengthening of African vaccine manufacturing capacity. The outbreak underscores the necessity of rethinking global health governance to ensure timely sustained support for endemic and interconnected regions.