Recommendations for the use of Monkeypox Modified Vaccinia Ankara Vaccines, Imvanex or Jynneos, by the intradermal route

1. While vaccine supplies remain limited, monkeypox vaccine may be administered intradermally (ID) for those aged 18 years and older. Two 0.1ml doses no less than 28 days apart are required. Available data regarding ID administration are based on two doses of vaccine so it is important that the vaccine course is completed.

2. Vaccinees should be informed that there is an increased rate of local reactogenicity associated with ID vaccination which may last up to six months in a third of vaccinees.

3. The vaccine can be administered ID in those with immunocompromise, although the immune response may be lower than in those who are immunocompetent.

4. ID administration into the volar aspect of the forearm should be performed by health professionals appropriately trained in the correct administration of ID vaccines.

5. A person who has received their first vaccine dose subcutaneously (SC) may receive the second dose ID. Those whose 18th birthday occurs between their first and second dose may complete the series with the alternative ID dosing.

6. When vaccine supplies are adequate, those who received their first vaccine dose ID may receive the second dose SC.

7. Those who have had previous smallpox vaccination require one vaccine dose, which can be given SC or ID. Those who are immunocompromised require two vaccine doses no less than 28 days apart regardless of previous smallpox vaccination.

8. NIAC strongly encourages further research in Ireland on vaccine effectiveness against monkeypox as the exact level and duration of protection are unknown with either SC or ID administration in line with WHO recommendations.

These recommendations are an update to recommendations made on 27 May and 22 July 2022. They are made in in the context of the current Public Health Emergency and limited availability of monkeypox vaccine. Adopting ID administration as an alternative to the standard SC administration will facilitate vaccination of a greater number as it could increase the numbers vaccinated five fold. These recommendations reflect a dynamic vaccination programme strategy. Recommendations may be updated when more information becomes available.