As Australia entered the third day of its vaccination drive its health minister told local media on Wednesday that two people had received incorrect coronavirus vaccine doses.
The two patients, aged 88 and 94, were given four times the recommended dose of the Pfizer vaccine.
Health Minister Greg Hunt said the human error was a reminder of safeguards during the rollout:
"I think it's very important that we are upfront. The safeguards that were put in place immediately kicked into action, a nurse on the scene identified the fact that a higher than prescribed amount of the dose was given to two patients."
"Both patients are being monitored and both patients are showing no signs, at all, of an adverse reaction."
Meanwhile, after several weeks of zero COVID-19 cases, two Australian states will loosen their restrictions this week.
In New South Wales, up to 30 people can kick up their heels on dance floors at indoor venues, and households can host 50 guests, up from 30.
Australia has recorded around 29,000 COVID-19 cases and just over 900 deaths since the pandemic began.