The global vaccine group Gavi will buy 500 000 doses of Bavarian Nordic's mpox vaccine, its first purchase of the shot to help battle an outbreak in parts of Africa, the group said on Wednesday.

In 2024, there have been more than 25 000 suspected mpox cases and 723 deaths in Africa, mainly in the Democratic Republic of Congo, according to the World Health Organization, which has declared the outbreak a global health emergency.

Gavi, a public-private alliance which co-funds vaccine purchases for low-income countries, said it will spend up to $50-million on the plan, which includes the transportation, delivery and costs of administering the vaccines. The doses are due to be delivered this year.

Around 3.6-million doses of mpox vaccine have already been pledged to the DRC by rich nations which have stockpiles, the World Health Organization has said, but only a small portion has arrived so far. The WHO approved the vaccine for use on Friday last week.

Gavi's purchase, using a new facility set up after the Covid-19 pandemic to respond quickly to public health emergencies, could speed up the response in Congo and other affected countries.

The price of the vaccine was not disclosed. The $50-million investment would equate to around $100 per vaccine, lower than previous estimates. But the actual price is likely lower still because the money includes funding for the storage and roll-out.

Gavi chief executive Sania Nishtar said the priority was working with partners "to turn these vaccines into vaccinations as quickly and effectively as possible and, over time, to build a global vaccine stockpile."

The deal will significantly increase the availability of mpox vaccine for African countries, Bavarian Nordic chief executive Paul Chaplin said. Last week, the company said it would push back some existing orders to 2025, based on US government contracts, to focus on market needs now.

Mpox, which spreads through close contact and typically causes flu-like symptoms and pus-filled lesions, has been a public health problem in parts of Africa for decades. But vaccines have never previously been available outside clinical trials in affected countries in Africa, even after a different strain of the virus spread globally in 2022 and high-income countries used vaccines to help stem the outbreak.