The national Covid vaccination systems deployed in response to the pandemic, was upgraded in January and indeed continues to be developed and refined in response to the emerging needs of the Covid vaccination programme. Decisions regarding the definition of which cohorts/ groups of people will receive which vaccine, and in what type of location eg hospital, GP surgery, mass vaccination clinic, among others, can have significant impacts on the configuration of the system. A dedicated team with technical expertise within the HSE are engaged in this work with technical partners IBM and Salesforce.