The cowpox vaccine has a certain chance of immunizing against the monkeypox virus, but there is no guarantee of 100% prevention. Cowpox virus, monkeypox virus and smallpox virus all belong to the Orthopoxviridae family and double-stranded DNA viruses, and there are some similarities and differences in their genetic profiles. Although the symptoms of monkeypox and smallpox are more similar, monkeypox virus is less infectious and pathogenic than smallpox virus. The cowpox vaccination is mainly used for smallpox virus. Since monkeypox and smallpox are of the same virus genus and have structural similarities, the antibodies induced by cowpox vaccine can prevent the invasion of monkeypox virus on human body to a certain extent. That is to say, cowpox vaccination can prevent monkeypox to a certain extent, but it does not guarantee 100% prevention of monkeypox. For those who have not been vaccinated against cowpox, they are more susceptible to monkeypox. It is recommended to pay attention to personal protection in monkeypox-endemic areas and avoid contact with wild animals, especially primates, so as to avoid monkeypox, which will pose a certain threat to one’s health.