Some gay and bisexual men at higher risk of catching monkeypox should be offered a vaccine, say UK health officials.
This could help to control the recent outbreak of the rare virus in the UK in which 793 people have been infected so far.
Monkeypox is not defined as a sexually-transmitted infection.
But it can be passed on by close contact during sex, and with bedding, towels and skin.
The UK Health Security Agency (UKHSA) says that a vaccine designed to protect against smallpox, called Imvanex, will help protect people who could be exposed to monkeypox.
The vaccine is effective against monkeypox because it is from the same family of viruses. Its use has been signed off by the UK’s vaccine experts, the Joint Committee on Vaccination and Immunisation (JCVI).
Health officials say they are continuing to see “a notable proportion of cases in gay, bisexual and other men who have sex with men”.
They say they hope rolling out vaccines to those at higher risk will “break chains of transmission”.
A doctor may now advise vaccination for someone who, for example, “has multiple partners, participates in group sex or attends ‘sex on premises’ venues”, UKHSA says.
At-risk men should not come forward for a vaccine until contacted.
More details are due to be set out shortly on how they can take up the offer.