The World Health Organization (WHO) has announced the prequalification of the MVA-BN vaccine, manufactured by Bavarian Nordic, as the first vaccine against mpox. This decision marks a significant step in combating the ongoing outbreak, particularly in Africa, where the disease has infected over 20,000 people this year. The prequalification is expected to facilitate timely and increased access to this vital product in communities with urgent needs, aiming to reduce transmission and contain the outbreak.
Vaccine Details and Administration
The MVA-BN vaccine, already approved for use in adults in Europe and the United States, can be administered in two doses, four weeks apart, to individuals 18 years and older. This regimen has an estimated effectiveness of 82%. In situations where vaccine supply is limited, the WHO recommends a single dose, which provides approximately 76% effectiveness. The WHO also noted that the vaccine may be used “off-label” for children, pregnant women, and immunocompromised individuals in outbreak settings where the benefits outweigh potential risks.
WHO's Stance and Recommendations
WHO Director-General Tedros Adhanom Ghebreyesus emphasized the importance of this 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 future.” He further urged, “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.”
Impact on Vaccine Access and Distribution
The WHO's prequalification is expected to accelerate procurement by governments and international agencies such as Gavi and UNICEF. It can also help fast-track regulatory approval by countries worldwide. Dr. Yukiko Nakatani, WHO Assistant Director-General for Access to Medicines and Health Products, noted that this decision will “help accelerate ongoing procurement of the mpox vaccines by governments and international agencies…to help communities on the frontlines of the ongoing emergency in Africa and beyond,” and will assist national regulatory authorities to “fast-track approvals, ultimately increasing access to quality-assured mpox vaccine products.”
Global Mpox Situation
Since the global outbreak in 2022, over 120 countries have confirmed more than 103,000 cases of mpox. In 2024 alone, there have been 25,237 suspected and confirmed cases and 723 deaths from different outbreaks in 14 African countries (as of September 8, 2024). The WHO has declared the escalating mpox outbreak in the Democratic Republic of the Congo and other countries a Public Health Emergency of International Concern (PHEIC).
Diagnostic Developments
In related news, the WHO has also approved the first emergency use diagnostic test for mpox, developed by Abbott Laboratories. This test, named the Alinity m MPXV assay, uses real-time PCR technology to detect mpox virus DNA from human skin lesion swabs, facilitating accurate and timely diagnosis. The WHO is currently reviewing three more mpox diagnostic tests for potential emergency use authorization.
