The World Health Organization (WHO) has been authorized to use the monkeypox (mpox) vaccine on adults.

The WHO said on Friday that the MVA-BN vaccine—the first against mpox—has been added to its prequalification list.

To be approved for prequalification, the manufacturer, in this case Bavarian Nordic A/S, submits data to the European Medicines Agency, the regulatory agency that assesses the information.

The WHO’s Strategic Advisory Group of Experts on Immunization also reviewed and approved the mpox vaccine “for persons at high risk of exposure.”

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

The WHO stated in August there is an increase in cases in the Democratic Republic of Congo. Common symptoms include skin rash, swollen lymph nodes, fever, headache, muscle aches, back pain, low energy, and mucosal lesions.

Most people recover from the virus with supportive care, the WHO said, but some become severely ill.

“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,” WHO Director-General Tedros Adhanom Ghebreyesus said. “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.”

The vaccine is given as a two-dose injection four weeks apart.

Yukiko Nakatani, the WHO’s assistant director-general for Access to Medicines and Health Products, said the vaccine’s approval will now speed up distribution for African countries where mpox is hitting the hardest.

“The decision can also help national regulatory authorities to fast-track approvals, ultimately increasing access to quality-assured mpox vaccine products,” she said.

On Friday, the Africa Centers for Disease Control and Prevention (Africa CDC) announced the postponement of a health conference in Morocco in November due to “this devastating Mpox outbreak” that it said has “spread across all five regions.”

The Africa CDC said mpox has taken a heavy toll on children—who make up 60 percent of the cases—in addition to people who have HIV/AIDS.

The WHO said there is a 76 percent effectiveness rate for those who are given the vaccine before exposure, and 82 percent for those who take both the first and second dose.

Taking the vaccine after exposure “is less effective,” the WHO said.

The WHO declared in August the mpox outbreak in Africa a public health emergency of international concern.

In 2024, there were 723 reported deaths—about 2.9 percent—of 25,237 confirmed cases in 14 African countries, based on data accumulated by Sept. 8, 2024.