A consultant doctor at the Coombe Hospital in Dublin vaccinated two family members with a vial they took home with them from the clinic.
It is one of the findings of a review published into what happened to 16 'leftover' doses at the hospital in January.
Fears that vaccines might be 'leftover' at the Coombe's vaccine clinic emerged in the evening of Friday January 9th.
A group of 11 consultants, clinical staff and administrators made the decision to give it to staff relatives.
There was no consensus over what criteria to apply - though four people turned it down when it was offered to them.
One staff member told investigators they were surprised to see someone so young arriving to receive a dose.
After 10.00pm, one of the consultants took a diluted vaccine vial home and injected two members of their family.
Nine of those injected were aged over 70 - the rest are described in the report as being of "varying age".
The review has found there was no "material discussion" about alternatives to giving the doses to family members.
That is despite the fact the Coombe had been injecting local GPs since that morning, after getting more doses than expected out of the vials throughout the week.
The hospital board says "lessons must and will be learnt" and that it has "started a process to address the implications".
Reporting by: Stephen Bourke