The World Health Organization (WHO) has added the MVA-BN vaccine to its prequalification list. This makes it the first approved vaccine for Mpox (formerly known as monkeypox). This approval will increase vaccine access in high-need communities, helping to reduce transmission and control ongoing outbreaks. WHO based its decision on data from Bavarian Nordic A/S and a review by the European Medicines Agency.
Background on Mpox
The WHO declared the ongoing Mpox outbreak a Public Health Emergency of International Concern (PHEIC) on August 14, 2024. Over 103,000 cases have been confirmed in 120 countries since 2022. In 2024 alone, there were 25,237 confirmed cases and 723 deaths across 14 African nations, highlighting the urgent need for a vaccine. More on Mpox here.
Vaccine Details
Dr. Tedros Adhanom Ghebreyesus, WHO Director-General, praised the MVA-BN vaccine’s prequalification, stating, “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 the future.” He called for urgent procurement and equitable distribution to prevent further infections and save lives.
The MVA-BN vaccine is administered to adults as a two-dose injection, with doses given four weeks apart. It can be stored at 2–8°C for up to eight weeks after initial cold storage.
Dr. Yukiko Nakatani, WHO Assistant Director-General for Access to Medicines and Health Products, said, “The WHO prequalification of the MVA-BN vaccine will help accelerate ongoing procurement of the Mpox vaccines by governments and international agencies such as Gavi and Unicef to help communities on the frontlines of the ongoing emergency in Africa and beyond.”
Target Groups and Effectiveness
WHO’s Strategic Advisory Group of Experts (SAGE) on Immunization has recommended the vaccine for high-risk individuals during outbreaks. Although the vaccine isn’t yet licensed for those under 18, WHO advises its “off-label” use for children, pregnant individuals, and immunocompromised individuals in outbreak settings.
In supply-constrained settings, WHO recommends a single-dose vaccination strategy. A single-dose MVA-BN vaccine provides 76% effectiveness, while the two-dose schedule boosts effectiveness to 82%. Pre-exposure vaccination is more effective than post-exposure vaccination.
Safety and Ongoing Data Collection
Clinical trials and real-world use during the global outbreak have demonstrated a good safety profile for the MVA-BN vaccine. WHO emphasizes the need for more data on the vaccine’s safety and effectiveness, especially as new virus strains emerge.
Since August 7, 2024, when WHO triggered the emergency use listing for Mpox vaccines, it has assessed the product and programmatic suitability of the MVA-BN vaccine. Dr. Rogerio Gaspar, WHO Director for Regulation and Prequalification, noted, “We are progressing with prequalification and emergency use listing procedures with manufacturers of two other mpox vaccines: LC-16 and ACAM2000.”
The Burden and Response
Africa faces a severe shortage, needing an estimated 10 million Mpox vaccines. The Democratic Republic of the Congo, which accounts for most cases, only received 100,000 vaccines earlier this month despite reporting over 700 deaths and 22,000 cases this year, largely from the new Clade 1b strain.
In response, Global Alliance has purchased half a million Mpox vaccines for Africa through its First Response Fund. Read more here