(NEXSTAR) – A 23-year-old woman is recovering after she was given six shots of the Pfizer BioNTech COVID-19 vaccine at a hospital in Tuscany, Italy.

The hospital’s parent company confirmed the error, which apparently happened after a nurse mistakenly injected her with the entire vial of vaccine, equivalent to six doses.

The patient is a grad student who had to get the vaccination for her clinical psychology program. She told local newspaper Corriere Della Sera she immediately knew something was wrong because the nurse looked distressed and immediately went to talk to a doctor.

Daniella Gianelli, a spokeswoman for the Noa hospital, told CNN the health care worker realized what happened after seeing the other five syringes meant for the vial.

The woman was held at the hospital for observation after the injection Sunday morning and discharged 24 hours later. She told Corriere Della Sera she had minor symptoms at the hospital – headache, fatigue and shivering – and now has “severe pain at the injection site,” exhaustion as well as fear over any possible ramifications.

Gianelli told CNN she is “in good health” but doctors will continue to monitor her after the “massive dose of vaccine.”

There have been other mix-ups that have made headlines during the roll-out of COVID-19 vaccinations. Several people received empty shots during a vaccination drive at a Virginia Kroger location.