Mpox emergence and new vaccines: a story of susceptibility

Mpox is a smallpox-like disease caused by the monkeypox virus. In 2022, a global outbreak of mpox resulted in more than 113 000 cases. Just a year later, a different strain of mpox caused the largest ever outbreak in Africa, with over 46 000 cases. Previous mpox epidemics were small, primarily occurred in Africa, had a case-fatality rate of 1-10%, and spread readily through contact with lesions and fomites. The new outbreaks had features never seen before with mpox - milder presentations and sexual transmission - that, together, fueled much wider dissemination of the disease. In this review, we discuss the potential drivers of increased mpox outbreaks, the efficacy of currently licensed vaccines, and the development of new vaccines. With a more susceptible human population than ever before, we are preparing for future mpox outbreaks with a better understanding of its transmission and more preventive tools.