WHO Declares Mpox a Global Health Emergency for Second Time as New Strain Spreads Across Africa

The World Health Organization declared mpox a public health emergency of international concern on 14 August 2024, its second such declaration in two years, as a new and more dangerous variant of the virus spread rapidly through the Democratic Republic of Congo and began crossing into neighbouring countries for the first time. The declaration was made by WHO Director-General Dr. Tedros Adhanom Ghebreyesus following a meeting of the organisation's Emergency Committee, which found that the conditions for a public health emergency of international concern — the WHO's highest level of global health alert — had been met. The African Union's Africa CDC made a parallel declaration of a continental security emergency on the same day. At the centre of the outbreak is clade Ib, a newly identified subvariant of the mpox virus that first emerged in eastern Democratic Republic of Congo. Preliminary epidemiological data indicated that clade Ib spread more readily through close and sexual contact than previously documented strains, and early case reports suggested it was associated with higher rates of severe illness and fatality. By August 2024, the strain had been detected in Burundi, Uganda, Rwanda, and Kenya — countries that had not previously reported sustained mpox transmission. The 2024 emergency was distinct in character from the first WHO mpox public health emergency of international concern, declared in July 2022. That outbreak, which spread globally to more than 100 countries primarily through sexual networks among men who have sex with men, was eventually brought under control through vaccine deployment and behavioural change, and the emergency was lifted in May 2023. The 2024 crisis was driven instead by a different transmission pattern in central and eastern Africa, affecting a broader population including women, children, and healthcare workers. The declaration placed immediate pressure on vaccine manufacturers and high-income nations to accelerate the transfer of mpox vaccines to affected African countries. Two vaccines provide protection against mpox: JYNNEOS, developed by Bavarian Nordic, a modified vaccinia Ankara vaccine approved in the United States and European Union; and ACAM2000, a live smallpox vaccine. Both remained in very limited supply in sub-Saharan Africa at the time of the emergency. Public health experts used the outbreak to renew calls for reform of international mechanisms governing vaccine equity, pointing out that the countries bearing the heaviest burden of the outbreak were among the least equipped to respond. Surveillance capacity, laboratory infrastructure, and contact tracing resources in conflict-affected eastern DRC were described as severely constrained. The situation also highlighted the importance of strengthening health systems in regions where infectious disease outbreaks are most likely to emerge, a priority that had been extensively discussed but incompletely addressed in the years following the COVID-19 pandemic.