Potential of MRNA vaccines for mpox prevention: current evidence and future directions

In 2022, the presumption of monkeypox (mpox) to be of limited epidemiology shifted when a global outbreak was announced. Being a member of the Orthopoxvirus genus in the Poxviridae family, it'd been reported in over 82 countries with over 17 000 confirmed cases by July 2022, thus showing its capability for spreading rapidly. As the smallpox vaccine offers 85% cross-immunity against mpox, the outbreak highlighted the attenuation of global immunity against orthopoxviruses after the cessation of vaccination campaigns against smallpox. The mortality of this virus is higher in vulnerable populations such as children, pregnant women, the elderly, and immunosuppressed individuals. With treatment methods being limited to off-label use of antivirals, the need for urgent and efficient preventative measures is emphasized. At present, JYNNEOS (Modified Vaccinia Ankara-Bavarian Nordic), showing favorable safety, and ACAM2000, a live attenuated virus with a high risk of side effects, are two vaccines that are indicated for mpox immunization. However, neither of them has proven full safety, efficacy, and widespread accessibility against mpox. Hence, the use of mRNA vaccines has emerged as a better alternative to traditional vaccinations, as they leverage synthetic messenger RNA to instruct host cells to produce antigens, eliciting both humoral and cellular immune responses. Though they provided rapid scalability, adaptability to emerging viral variants, and an established safety profile after the COVID-19 pandemic, their usage in preventing mpox remains an area of research. This paper elucidates the potential of mRNA technology to address the unmet needs in mpox prevention. It also highlights the need for genomic surveillance, immunological insights, and innovative delivery systems.