The co-leader of the Social Democrats, Róisín Shortall, has welcomed the publication of the Vaccination Strategy document, but said clarification is required on the IT system and a number of other issues.
Speaking on RTÉ's Drivetime, she said while a company has been selected, the contract has not been awarded yet.
The CEO of the HSE, Paul Reid, said a partnership between IBM and Salesforce has been selected to manage the vaccine IT system.
Ms Shortall said while a temporary Information and Communications Technology (ICT) system will be set up, it is really important that it is compatible with the permanent system that is going to be set up by the new company.
She said clarification is also required on the Individual Health Identifier, which identifies each patient and every time they attend a GP or hospital that they do not have to give their medical history from scratch.
She said it is important that there are safeguards for Data Protection and confidentiality around people's health information.
She said: "There's a whole ICT area that hasn't been finalised yet and we need to have assurances that that will all be in place without further delay."
She said those assurances should be given in the Dáil and while provision has been made for statements to be taken on the Vaccination Strategy late on Thursday evening, she said "there's going to be very limited opportunity for any kind of interaction between the Minister for Health and the Government".
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The Chair of the IMO's GP Sub Committee Dr Denis McCauley said the Individual Health Identifier was due to come into place this year, but was delayed because of Covid-19.
Speaking on the same programme, he said there is a template in place, so hopefully it can be rolled out in a reasonably straightforward way.
The Irish College of General Practitioners Covid-19 adviser, Dr Mary Favier said the announcement of the plan is "a very welcome announcement" and that GPs are very much in agreement with the priorities and sequencing and looking at the more vulnerable groups.
She said she does not know at which point GPs will become involved in the roll-out of the vaccine, but it is likely they will not be involved in the very early stages, which will focus on people in residential care facilities.
She said there is precedent for vaccine certificates and they have been used in other countries, where people have to show they are vaccinated for yellow fever.
She said there are some logistical and ethical issues around vaccine certificates, so she said "it's very much for the future and we need to focus on the here and now".
Kingston Mills, Professor of Experimental Immunology at Trinity College Dublin, said getting back to normal will depend on how much vaccine we have to vaccinate the whole population.
Professor Mills said the logistics of this are going to be quite large to get it right.
He said "the safety side has to be very carefully monitored post vaccination" and that is facilitated if you have a thorough integrated ICT system, which is why we need it.
Meanwhile in the Dáil earlier Sinn Féin leader Mary Lou McDonald said there was concern that people with disabilities were being ignored in the roll out of the Covid-19 vaccines.
However, Taoiseach Micheál Martin described her remark as a very "reprehensible thing to say".
He said public health experts would engage with people with disabilities in terms of the roll out of the vaccine.