WHO Clears World's First Mpox Vaccine For Use In Some Areas

The World Health Organization (WHO) has announced the MVA-BN vaccine as the first vaccine against mpox to be added to its prequalification list. This is expected to facilitate timely and increased access to this vital product in communities with urgent need, to reduce transmission and help contain the outbreak, WHO said in a statement on its website.

WHO 'prequalification' and 'emergency use listing' are mechanisms used to evaluate quality, safety and efficacy of medical products, such as vaccines, diagnostics and medicines, and product suitability for use in a low- and middle-income country context.

WHO's assessment for prequalification of the mpox vaccine is based on information submitted by the manufacturer, Bavarian Nordic A/S, and reviewed by the European Medicines Agency, the regulatory agency of record for this vaccine.

"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," said WHO Director-General Dr Tedros Adhanom Ghebreyesus.

"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," Dr Ghebreyesus said.

The MVA-BN vaccine can be given to people over 18 years old as a two-dose injection, four weeks apart, WHO said. After prior cold storage, the vaccine can be kept at 2-8 degree Celsius for up to eight weeks, it said.

The WHO Strategic Advisory Group of Experts (SAGE) on immunisation reviewed all available evidence and recommended the use of MVA-BN vaccine in the context of an mpox outbreak for people at high risk of exposure, WHO said.

While MVA-BN is currently not licensed for people younger than 18 years, this vaccine may be used "off-label" in infants, children and adolescents, and in pregnant and immunocompromised people, WHO said. This means the vaccine use is recommended in outbreak settings where the benefits of vaccination outweigh the potential risks.

WHO has, however, emphasised the need to collect further data on vaccine safety and effectiveness under these circumstances.

Available data shows that a single-dose MVA-BN vaccine given before exposure has an estimated 76 per cent effectiveness in protecting people against mpox, with the two-dose schedule achieving an estimated 82 per cent effectiveness.

Vaccination after exposure is less effective than pre-exposure vaccination, WHO said.

The escalating mpox outbreak in the Democratic Republic of the Congo and other countries was declared a public health emergency of international concern by the WHO Director-General on August 14.

Over 120 countries have confirmed more than 1.03 lakh cases since the onset of the global outbreak in 2022. In 2024 alone, there were 25,237 suspected and confirmed cases, and 723 deaths from different outbreaks in 14 African nations, WHO said.