CALGARY -- Alberta Health Services is notifying 10 people who received a Pfizer vaccine at the Lethbridge Exhibition on April 29 that they may have mistakenly been given saline water diluent instead.

Officials were able to identify the window of time when the mistakes happened and say 10 people were seen, with five of them receiving the saline.

AHS will be directly contacting all 10 people to rebook their immunization appointment. 

"Only those individuals contacted directly by AHS are considered impacted by this issue," read a release.

"Though there is no impact on general public, we are informing the public of this case and our follow-up actions as a matter of transparency."

The mistake was discovered during a routine audit at the end of the day on April 29, when an unused vial of vaccine was found. The investigation involved interviews with staff, and a review of vaccine logs and electronic documentation.

"Diluent is part of the final vaccine product and is administered as part of the shot," read a release.

"Manufacturers of the COVID-19 vaccine provide vaccine and diluent in separate vials which are mixed together by the healthcare provider prior to administering the final vaccine product. There are no anticipated health effects from providing the saline to these impacted individuals. However, the saline solution itself does not provide protection against the COVID-19 virus."

Those impacted will be given a repeat dose on or after the 21-day mark from their first dose to help ensure vaccine efficacy and reduce any potential for side effects. 

Anyone with questions can call Health Link at 811.