The Department of Health is urging people to keep their allocated vaccination appointments.
Rescheduled second Covid-19 vaccines have increased significantly, with over 1,000 requests received in recent days.
Patricia Donnelly, Head of the Northern Ireland Vaccine Programme, said: “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.
“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.
“This is why second appointments are automatically generated when a first appointment is booked to allow us to plan ahead, taking into account issues such as supplies of the various vaccines and availability of vaccination slots.
"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. The same people who are running the vaccination centres and organising this very demanding vaccination programme are already busy. So it will take time.
“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.”
Subscribe or register today to discover more from DonegalLive.ie
Buy the e-paper of the Donegal Democrat, Donegal People's Press, Donegal Post and Inish Times here for instant access to Donegal's premier news titles.
Keep up with the latest news from Donegal with our daily newsletter featuring the most important stories of the day delivered to your inbox every evening at 5pm.