The Ministry of Health says up to 13 people who got their Covid-19 vaccines in the Canterbury DHB region earlier in August may have gotten a lower dose than intended.
Authorities stressed no patient harm would have come from the incident.
“But we acknowledge this would be concerning for the people involved,” the Ministry of Health said.
Of the group of 13, 12 have been contacted and are booked in for another dose of the vaccine.
“A range of methods is being used to contact the remaining person,” authorities said.
“Incidents of this nature are not common but it is important each is reported and acted on. DHBs and healthcare providers have systems in place to detect them when they do, including clinical oversight and strong quality assurance processes.”
The Ministry of Health said it had “worked closely” with the vaccination team in Canterbury.
The provider will also be implementing improvements and additional training for staff.
It follows an incident in Auckland that may have seen five people out of 732 injected with harmless saline solution instead of a Covid-19 shot at the Highbrook Vaccination Centre on July 12.