Around 15 Wellingtonians were given expired doses of the Covid-19 vaccine last week.
Capital and Coast DHB said the doses had expired within the previous 24 hours and were given to a small number of people at a clinic on October 14 and 15.
"This error was picked up quickly as part of regular, existing monitoring processes and the people affected have been contacted," a spokesperson said.
"Fewer than 15 people were affected."
"The incident is being reviewed and it is thought to be an isolated error, but as a precaution, remaining stock is being checked to ensure it is within the expiry date."