The World Health Organization (WHO) has officially prequalified the MVA-BN vaccine as the first vaccine specifically targeting mpox.
This milestone is expected to enhance the availability and accessibility of the vaccine, particularly in regions experiencing urgent needs, with the aim of curbing transmission and controlling outbreaks.
The prequalification approval process by WHO involves evaluating data provided by the manufacturer, Bavarian Nordic A/S, and an assessment by the European Medicines Agency (EMA). WHO Director-General Dr. Tedros Adhanom Ghebreyesus emphasized the significance of this development in the fight against mpox, both for current outbreaks in Africa and for future preparedness. He called for increased efforts in procurement, donations, and distribution to ensure equitable access to the vaccine.
The MVA-BN vaccine, which is intended for individuals aged 18 and older, is administered as a two-dose series with a four-week interval between doses. After initial cold storage, it can be maintained at a temperature of 2–8°C for up to eight weeks. The vaccine’s effectiveness has been estimated at 76% with a single dose given before exposure and approximately 82% with the full two-dose regimen. Post-exposure vaccination is less effective than pre-exposure.
WHO’s Strategic Advisory Group of Experts (SAGE) on Immunization has recommended the use of the MVA-BN vaccine during outbreaks for those at high risk, though it is not currently licensed for individuals under 18. The vaccine may be used off-label in children, pregnant individuals, and those with compromised immune systems if the benefits outweigh potential risks. Additionally, WHO suggests considering single-dose use in situations where vaccine supplies are limited, while continuing to gather data on its safety and efficacy.
Dr. Yukiko Nakatani, WHO Assistant Director-General for Access to Medicines and Health Products, noted that the prequalification of the MVA-BN vaccine will expedite procurement efforts by governments and international organizations such as Gavi and UNICEF. This step is also expected to support faster regulatory approvals by national authorities.
The WHO’s emergency use listing for mpox vaccines, triggered in August 2024, has led to assessments of additional vaccines like LC-16 and ACAM2000. Efforts are also underway to evaluate mpox diagnostic products. The recent declaration of a public health emergency of international concern (PHEIC) due to the surge in mpox cases in Africa underscores the urgency of these initiatives.
Since the onset of the global outbreak in 2022, over 120 countries have reported more than 103,000 mpox cases. The outbreak, particularly severe in the Democratic Republic of the Congo, has resulted in numerous fatalities. The WHO’s prequalification of the MVA-BN vaccine represents a critical step in addressing this ongoing public health challenge and improving response efforts.
ABC News, Reuters, Politico, Fierce Pharma, World Health Organization contributed to this report.
