Niagara Region Public Health is reaching out to clients who recently attended a vaccination clinic in Port Colborne.
On June 16th, six individuals received an injection of a harmless saline diluent instead of the COVID-19 shot.
Public Health is reaching out to 205 clients who had an appointment that day to book a repeat vaccination.
Only those who are contacted directly by Public Health are considered to have potentially impacted.
The error was discovered when the end-of-day audit determined that six extra doses not accounted for had been administered.
An additional vial of saline diluent was found, which suggested it had been offered to some clients without mixing it with the vaccine.
This means some of the clients will be receiving three vaccination doses, which Niagara Region Public Health says is safe.