The Department of Health is appealing for the public to keep their allocated Covid-19 vaccine dates following a surge of rescheduled second appointments.
The department said the number of people requesting an alternative second date for the jab had exceeded 1,000 over the past number of days.
It said adding significant changes to dates could “potentially jeopardise” the roll out.
Second appointments for the vaccine are generated automatically after the first one, with the public being given this date after they receive the vaccine.
The head of Northern Ireland’s vaccine programme said the planning around the vaccine was “highly complex” and urged people to keep the date of their second vaccination.
“I fully understand that we are all anxious to enjoy a more normal life including an opportunity to enjoy some of the things which have been denied us during the last 18 months,” she said.
“However this programme is a massive and highly complex logistical undertaking requiring intense planning. The ongoing cooperation of everyone to come forward for their second dose on their appointed date is crucial.
“Getting your second dose is not only vital in providing fuller and longer lasting protection against the virus, but also to enable the thousands of people working so hard managing the roll out to do so as effectively as possible.
“It is the responsibility of each of us to ensure we are available for our second appointment. So we ask that where possible you avoid making commitments that clash with the date of your second dose – that includes booking flights and hotels – please look for alternative dates.
“Where changing the date of the second dose is unavoidable – please be patient this will not happen immediately.
“Any large scale changes could potentially jeopardise the overall roll-out of the programme.
“The success of the vaccine programme in Northern Ireland has been built on an amazing public response which has seen over one million people receive their first dose.
“Their cooperation has played a major part in bringing us to where we are today. It is imperative however that we recognise how important it is, that in order to maintain that progress the full and effective roll out is maintained.”