The World Health Organization (WHO) has announced the addition of the MVA-BN vaccine to its prequalification list, making it the first vaccine against mpox (formerly known as monkeypox) to receive this approval.

This prequalification is expected to improve access to the vaccine in communities facing urgent needs, helping to reduce transmission and control the ongoing outbreak. WHO’s approval was based on a review of data submitted by the vaccine’s manufacturer, Bavarian Nordic A/S, and the European Medicines Agency.

WHO Director-General Dr. Tedros Adhanom Ghebreyesus highlighted the significance of this development, emphasizing that the prequalification marks an important step in combating mpox outbreaks in Africa and globally. He stressed the need for rapid scale-up in vaccine procurement, donations, and distribution to ensure equitable access alongside other public health measures to prevent infection and save lives.

The MVA-BN vaccine, approved for adults aged 18 and over, is administered as a two-dose injection, four weeks apart. Once removed from cold storage, the vaccine can be stored at 2–8°C for up to eight weeks. WHO Assistant Director-General for Access to Medicines and Health Products, Dr. Yukiko Nakatani, noted that the vaccine’s prequalification would accelerate procurement by governments and international organizations like Gavi and Unicef, benefiting communities affected by the mpox outbreak.

The WHO’s Strategic Advisory Group of Experts (SAGE) on Immunization has recommended the MVA-BN vaccine for high-risk groups in the context of mpox outbreaks. While the vaccine is not licensed for individuals under 18, it may be used “off-label” for children, pregnant women, and immunocompromised individuals in outbreak settings where the benefits outweigh the risks.

WHO also recommends administering a single dose of the vaccine in cases of limited supply. Data shows that a single dose given before exposure offers 76% protection against mpox, with the two-dose regimen increasing effectiveness to 82%. Vaccination after exposure is less effective.

The MVA-BN vaccine has demonstrated a strong safety profile and performance in both clinical trials and real-world use during the ongoing global outbreak since 2022. As new virus strains emerge and epidemiology evolves, WHO stresses the importance of continuing to gather data on vaccine safety and efficacy.

Following the emergency use listing triggered by the WHO on 7 August 2024, WHO has assessed the MVA-BN vaccine for suitability in combating the current outbreak. WHO Director for Regulation and Prequalification, Dr. Rogerio Gaspar, confirmed that procedures are underway for two other mpox vaccines—LC-16 and ACAM2000—while six mpox diagnostic products are also being considered for emergency use.

The escalating mpox outbreak in the Democratic Republic of the Congo and other countries led the WHO Director-General to declare a Public Health Emergency of International Concern (PHEIC) on 14 August 2024. Since the global outbreak began in 2022, over 120 countries have reported more than 103,000 cases of mpox. In 2024 alone, there have been 25,237 suspected and confirmed cases, with 723 deaths across 14 countries in the African region, according to data as of 8 September 2024.