Parents of children aged five to eleven who are considered at risk are being encouraged to get them vaccinated "without delay".
The Public Health Agency has issued a call for children who are classed in the clinical risk group or in a household with someone who is immunosuppressed to be offered the Covid vaccine.
While most children who contract the virus only suffer mild symptoms or have none at all, there are some with certain health conditions who are more at risk from it and more likely to go to hospital.
