The World Health Organization (WHO) has announced the prequalification of the MVA-BN vaccine, making it the first mpox vaccine to be added to its prequalification list. This decision is expected to significantly enhance timely access to the vaccine in communities facing urgent needs, thereby reducing transmission and aiding in outbreak containment.
The WHO's prequalification assessment was based on data submitted by the manufacturer, Bavarian Nordic, and a review conducted by the European Medicines Agency, which serves as the regulatory agency of record for this vaccine. The MVA-BN vaccine is indicated for adults 18 years and older, administered as a 2-dose injection with a four-week interval between doses. After initial cold storage, the vaccine can be stored at 2–8°C for up to eight weeks.
WHO's Response and Global Impact
"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," stated WHO Director-General Dr. Tedros Adhanom Ghebreyesus. He emphasized the need for urgent scaling up of procurement, donations, and rollout to ensure equitable vaccine access, alongside other public health tools, to prevent infections, halt transmission, and save lives.
Bavarian Nordic has indicated its readiness to increase production to meet the rising global demand for mpox vaccines. Thomas Duschek, communications partner at Bavarian Nordic, mentioned in an interview that the company is scaling up production and building inventory to fulfill anticipated orders for the year, ensuring surge capacity for potential future outbreaks or large orders. He stated, "This means that—in addition to our existing commitments—we will be able to supply a total of 10 million doses by the end of 2025, including up to 2 million doses this year."
Efficacy and Prevalence of Mpox
Recent data from the CDC, published in MMWR, highlights the effectiveness of the Jynneos mpox vaccine. The study reported that two doses of the Jynneos vaccine are highly effective in preventing mpox virus infection, with an estimated incidence rate of less than 0.8% in fully vaccinated individuals. From May 2022 to May 2024, the CDC reported 271 mpox cases in fully vaccinated individuals across 27 US jurisdictions. During the same period, among 32,819 probable or confirmed mpox cases, 24,507 (75%) occurred in unvaccinated individuals.
The global impact of mpox has been significant. In August, the Africa Centers for Disease Control and Prevention (Africa CDC) declared the ongoing mpox outbreak a Public Health Emergency of Continental Security (PHECS). WHO also declared mpox outbreaks in Congo and other parts of Africa as a global emergency. As of September 8, WHO reports that over 120 countries have confirmed more than 103,000 cases of mpox since the global outbreak began in 2022. In 2024 alone, there were 25,237 suspected and confirmed cases and 723 deaths from outbreaks across 14 countries in the African Region.
