Ireland's COVID-19 vaccination programme strategy is to distribute all available vaccine as quickly as is operationally possible, prioritising those who are most vulnerable to COVID-19.
The programme is based on the principles of safety, effectiveness and fairness, with the objective of reducing severe illness, hospitalisations and deaths from COVID-19 infection.
The immunisation programme in Ireland is based on the advice of the National Immunisation Advisory Committee (NIAC). The Committee's recommendations are based on the prevalence of the relevant disease in Ireland and international best practices in relation to immunisation. It makes recommendations on vaccination policy to the Department of Health. The NIAC review all data relating to COVID-19 vaccines on a rolling basis.
Following the recommendation for use of vaccines against COVID-19 by the European Medicines Agency (EMA) and authorisation for use by the European Commission, the NIAC develops guidance for their use in Ireland which is contained in the Immunisation Guidelines for Ireland. These guidelines are continuously updated and include guidance on all new vaccines as they are approved for use in Ireland.
The current Guidelines state:
There are currently four COVID-19 Vaccines authorised for use in Ireland. The vaccines are not interchangeable. For vaccines that have a two-dose schedule, the same vaccine should be used for both doses. The NIAC will continue to review the evidence concerning the safety and efficacy of a heterologous vaccination strategy (using a different vaccine for the first and subsequent doses of a multi-dose schedule) as it becomes available.
You can read the guidelines at: www.hse.ie/eng/health/immunisation/hcpinfo/guidelines/covid19.pdf.