The Covid-19 vaccine registration portal has opened for parents to register their children aged between 5-11.
Pre-registration for the cohort became available on Monday morning, with appointments expected to be offered "soon after registration".
The HSE said clinical trials have shown the vaccine is "highly effective at preventing Covid-19 in children".
"Though serious illness from Covid-19 is rare in this age group, they are even less likely to become seriously ill with Covid-19 if they are vaccinated.
"All vaccines are tested before they are approved for use in Ireland by the European Medicines Agency," a statement from the HSE said.
Parents who are unsure as to whether they wish to register their child for a vaccine are urged to get information from a trusted source, such as the HSE website or a medical professional.
The HSE has also provided dedicated information for parents, including the benefits and risks of the vaccine.
Children in the 5-11 age group will be offered a reduced dose of the Pfizer/BioNTech vaccine, in line with recommendations from the National Immunisation Advisory Committee (Niac). Two doses of the vaccine will be administered approximately three weeks apart.
In order for a child to receive the vaccine, a parent or legal guardian will be required to give their consent.
The parent/guardian will need to attend the vaccine appointment with the child in order to give their consent if they have not done so online prior to the appointment or if they registered the child for the vaccine over the phone.
The HSE said the quickest way to register a child is online via the HSE website. To register online, a PPS number, Eircode, mobile number and email address are required.
Those who wish to register over the phone, including those whose children do not have a PPS number, can call HSELive on 1800-700 700.
Following registration, the parent/guardian will receive a text message with the child's appointment details, with jabs due to be administered in vaccination centres.