The smallpox vaccine is to be extended for people at high-risk of monkeypox infection.
Health Minister Stephen Donnelly made the announcement following recommendations from the National Immunisation Advisory Committee (NIAC) to the Interim Chief Medical Officer (CMO).
NIAC has recommended vaccination should be offered to gay and bisexual men, as well as other Men who have Sex with Men, and those at high-risk of unprotected exposure.
It says two doses of the smallpox vaccine should be given 28 days apart to as many high-risk individuals "as soon as practicable."
Minister Donnelly says most people recover in a few weeks.
"I welcome these recommendations which represent an important step in our ongoing response to the monkeypox outbreak and help protect those at high risk of exposure to monkeypox.
"Monkeypox is usually a self-limiting illness, and most people recover within a few weeks.
"However the rapid spread of infection necessitates further measures beyond those currently in place.
"The evidence suggests this approach to targeted pre-exposure prophylaxis may be highly efficient in controlling further spread of the disease."
Interim CMO, Professor Breda Smyth, adds: "These recommendations reflect a strengthening of measures to control disease transmission and ensures that our response to this evolving situation is informed by the best available evidence.
"I strongly encourage those with symptoms of infection to seek medical advice and follow the public health guidance."
Latest available data from the HPSC shows it has been notified of 69 confirmed cases of monkeypox in Ireland.
Last week, the European Medicines Agency (EMA) recommended the approval of the smallpox vaccine Imvanex to protect adults from monkeypox.
The medicine has been used in the European Union since 2013 to prevent smallpox.
Vaccination against smallpox has been seen to be around 85% effective in preventing monkeypox, the World Health Organisation (WHO) says.
It has declared the outbreak a public health emergency of international concern.
Europe has also been singled out as the only global region where the risk of infection is high.