The monkeypox virus is closely related to the virus that causes smallpox, which is why medical experts say the vaccine can help to protect people.
The head of the World Health Organization has said that the monkeypox outbreak is one of the major problems facing the world right now.
The outbreak of the virus which has seen 20 cases in the UK with more expected to be reported today. There have been around 80 cases in Europe, the United States, Australia, Canada and Israel. Read more about what the WHO chief had to say here.
