Dozens of Covid vaccines due to be given to elderly people had to be destroyed after a fridge malfunctioned.
Up to 10 vials delivered to Cleary House in Letterkenny could not be used after they became "unfit for purpose."
A vial can contain a number of vaccine doses.
Family members of people due for vaccination claim that the doses were incorrectly stored in a fridge at the centre.
The HSE confirmed that some vaccines had to be disposed of after an "incident".
A spokesperson said: “We regret that this incident has taken place. An incident report has been completed and all necessary processes will be followed to ensure there is no reoccurrence.”
A number of former residents of St. Conal’s Hospital now in residence at various locations in Donegal and others in ‘independent living’ circumstances were scheduled to be vaccinated at Cleary House, depending on supplies coming onstream.
Cleary House is a Mental Health Supervised Residential Unit (SRU).
The HSE confirmed that an issue surrounding a fridge was the reason why the vaccines had to be destroyed.
A spokesperson confirmed: “HSE Community Healthcare Organisation Area 1 wish to confirm that there was a non-clinical incident at Cleary House, facility for Mental Health Service Users in Letterkenny, Donegal on Wednesday 24th of March involving 10 vials of vaccine.
"This was due to a technical issue with a fridge at the facility, and unfortunately these vials could not be used.
"We regret that this incident has taken place.
"It is important to note that all service users scheduled for the clinic (33 in total) still received their vaccine at the clinic and that this incident did not impact on them.
"Residents from other Mental Health Supervised Residential units in Donegal Town, Carndonagh and Dungloe have received their vaccination in line with the scheduled vaccination programme.”
