The World Health Organisation said on Friday it had cleared Bavarian Nordic's vaccine as the first shot against mpox.
The approval, known as a pre-qualification, is an official list of medicines used as a benchmark for procurement by developing countries.
"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 Dr Tedros Adhanom Ghebreyesus said.
Mpox, a viral infection that spreads through close contact and is usually mild but can kill, was declared a public emergency of international concern by the WHO last month.