COVID-19 Vaccine Mistake: Woman Accidentally Given 6 Pfizer Doses

An Italian woman was accidentally given six doses of the COVID-19 vaccine at Noa Hospital in Massa, Tuscany. It was reportedly a result of human error.

A 23-year-old woman in Italy was set to receive the Pfizer-BioNTech COVID-19 vaccine Sunday. As an intern at Noa Hospital's psychology department, she could get her vaccine before others in her age group, CNN reported. However, instead of receiving one dose of the vaccine, she mistakenly received six.

The mistake happened because the nurse had an "attention lapse," CBS News said, citing Dr. Tommaso Bellandi, director of patient security for northwest Tuscany. It was reportedly an "extremely busy" day and the nurse thought the vaccine in the vial was already diluted.

According to the Centers for Diseases Control and Prevention (CDC), each vial of the Pfizer-BioNTech vaccine contains up to six doses and must be mixed with a diluent before being administered. To do this, each dose must be placed in separate vials to be diluted, Bellandi explained. However, the nurse mistakenly administered all the undiluted liquid to the patient.

"They are both transparent liquids of the same density. Unfortunately, this contributed to the error," Bellandi said further.

The nurse quickly realized the mistake and alerted the patient, the attending doctor, health authorities and the patient's family.

The woman was generally considered to be in good health and had no underlying conditions, Daniella Gianelli, a spokesperson from the hospital, told CNN. She was kept at the hospital where she was observed for 24 hours. She was also given fluids and fever and anti-inflammatory medications as preventive measures, according to CBS News. Without having manifested adverse side effects apart from pain at the injection site, she was discharged Monday.

Amid the global vaccine roll-out, there have also been other cases wherein patients are given multiple doses at once. In Israel, for instance, a pharmacist was given four doses of the Pfizer-BioNTech vaccine as the health worker who gave the inoculation reportedly wasn't aware that the vial contained multiple doses. The patient then only experienced minor side effects including redness at the injection site.

As for the patient in Italy, the hospital will continue to monitor her immune response and whether she would still need another dose, CBS News noted.