The World Health Organization (WHO) has officially added the MVA-BN vaccine to its prequalification list, marking the first vaccine against mpox to receive this endorsement. This crucial development is expected to accelerate access to the vaccine in communities facing high transmission rates, helping to contain ongoing outbreaks.

The WHO's prequalification process, which was based on an evaluation of data provided by Bavarian Nordic A/S and reviewed by the European Medicines Agency, aims to ensure that the MVA-BN vaccine is of high quality and suitable for large-scale procurement. The move is seen as a critical step in addressing the spread of mpox, particularly in Africa, where outbreaks have escalated.

Dr. Tedros Adhanom Ghebreyesus, WHO Director-General, emphasized the importance of this approval, stating, "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, administered as a two-dose injection four weeks apart, is currently authorized for individuals over 18 years of age. Once removed from cold storage, it can be stored at temperatures between 2°C and 8°C for up to eight weeks, making it suitable for areas with limited refrigeration infrastructure.

Dr. Yukiko Nakatani, WHO Assistant Director-General for Access to Medicines and Health Products, said the prequalification "will help accelerate ongoing procurement of mpox vaccines by governments and international agencies such as Gavi and Unicef, helping to protect vulnerable communities."

The WHO's Strategic Advisory Group of Experts (SAGE) on Immunization has recommended the MVA-BN vaccine for people at high risk of mpox exposure. Although not licensed for individuals under 18, the vaccine may be used "off-label" for infants, children, pregnant women, and immunocompromised individuals during outbreaks.

In areas with constrained vaccine supply, WHO has recommended single-dose vaccination, which has demonstrated 76% effectiveness in preventing mpox before exposure, compared to 82% with the two-dose schedule. The effectiveness of post-exposure vaccination is less robust.

WHO has also emphasized the need for continued data collection on the vaccine's safety and performance, particularly as new virus strains emerge. The MVA-BN vaccine has shown a strong safety profile in clinical trials and real-world use during the global outbreak, which began in 2022.

As of 2024, over 120 countries have reported more than 103,000 cases of mpox. In 2024 alone, 25,237 suspected and confirmed cases and 723 deaths were recorded across 14 African countries.

With mpox declared a Public Health Emergency of International Concern (PHEIC) by WHO on August 14, 2024, the organization is pushing for urgent action. WHO is also assessing two additional mpox vaccines—LC-16 and ACAM2000—and exploring diagnostic products to enhance global response efforts.