The World Health Organization (WHO) has announced the MVA-BN vaccine as the first vaccine against Mpox to be added to its prequalification list.

The prequalification approval is expected to facilitate timely and increased access to this vital product in communities with urgent need, to reduce transmission and help contain the outbreak.

WHO’s assessment for prequalification is based on information submitted by the manufacturer, Bavarian Nordic A/S, and review by the European Medicines Agency, the regulatory agency of record for this vaccine.

“This first prequalification of a vaccine against mpox is an important step in our fight against the disease, both in the context of the current outbreaks in Africa, and in future,” said WHO Director-General Dr Tedros Adhanom Ghebreyesus. “We now need urgent scale up in procurement, donations and rollout to ensure equitable access to vaccines where they are needed most, alongside other public health tools, to prevent infections, stop transmission and save lives.”

The MVA-BN vaccine can be administered in people over 18-years of age as a 2-dose injection given 4 weeks apart. After prior cold storage, the vaccine can be kept at 2–8°C for up to 8 weeks.

The WHO Strategic Advisory Group of Experts (SAGE) on Immunization reviewed all available evidence and recommended the use of MVA-BN vaccine in the context of an mpox outbreak for persons at high risk of exposure.

While MVA-BN is currently not licensed for persons under 18 years of age, this vaccine may be used “off-label” in infants, children and adolescents, and in pregnant and immunocompromised people. This means vaccine use is recommended in outbreak settings where the benefits of vaccination outweigh the potential risks.

Available data shows that a single-dose MVA-BN vaccine given before exposure has an estimated 76% effectiveness in protecting people against mpox, with the 2-dose schedule achieving an estimated 82% effectiveness. Vaccination after exposure is less effective than pre-exposure vaccination.

Over 120 countries have confirmed more than 103 000 cases of mpox since the onset of the global outbreak in 2022. In 2024 alone, there were 25 237 suspected and confirmed cases and 723 deaths from different outbreaks in 14 countries of the African Region (based on data from 8 September 2024).