Woman Accidentally Vaccinated With Four Pfizer Doses

A 23-year-old woman in Italy‘s central Tuscany region was accidentally administered four doses of the Pfizer vaccine on Sunday, but ended up discharged after 24 hours when she did not appear to suffer any severe effects.

Agence France-Presse reported Italian health officials initially said the young woman was injected with six doses, but corrected their error on Tuesday.

The woman, a clinical psychology trainee in the town of Massa, was scheduled to receive her first dose of the vaccine as a health worker, according to the news agency Agenzia Giornalistica Italia (AGI). But instead of being given a single Pfizer dose, she was accidentally injected with four.

Upon realizing her mistake, the Noa Hospital nurse who had administered the vaccine immediately informed the patient.

The young woman was placed under observation, during which she was treated with paracetamol and fluids. AGI reported she was discharged after 24 hours.

Dr. Antonella Vicenti, the hospital’s director of infectious diseases, said the young woman “did not have fever and did not have any pain except for pain at the inoculation site, nor any other manifestations,” according to CBS News, though she was “a bit frightened.”

The incident prompted a report to the Italian Medicines Agency and a police visit at the hospital to gather more information, according to La Nazione.

CBS News reported Dr. Tommaso Bellandi, director of patient security for northwest Tuscany’s health authority, said the mix-up had taken place because the nurse was distracted and failed to dilute the doses.

“She thought that the dilution had taken place,” Bellandi said, according to CBS News. “They are both transparent liquids of the same density. Unfortunately, this contributed to the error.”

The young woman’s mother told La Nazione her daughter first noticed something had gone wrong when she saw the nurse “sweating and hyperventilating.”

“It seems quite clear to me that there was a gross error on the part of those who managed my daughter’s vaccination,” her mother said. “Now all that remains is to hope that there are no adverse reactions of particular gravity.”

Vicenti said the young woman “at this time will certainly not have side effects,” according to CBS News, adding studies on the vaccine demonstrated people who had received up to five times the recommended dose did not suffer adverse reactions.

However, long-term effects on her antibody levels remain to be seen, she said. The hospital plans to conduct regular blood tests in an effort to monitor her immune response and determine whether a second vaccine dose is still possible, CBS News reported.

AGI said the case was the first of its kind in Italy.

In December 2020, eight German nursing home employees were administered five times the recommended dose of the Pfizer vaccine. Four of them were admitted to the hospital for observation after experiencing flu-like symptoms.

Earlier this month, several people who were vaccinated at the Queen Margaret University in Edinburgh, Scotland were accidentally given twice the normal dose. Those affected were told they were at increased risk of experiencing arm soreness and flu-like symptoms.

A more severe incident took place in Ohio earlier this year, when a 91-year-old man was hospitalized after a mix-up resulted in him receiving two shots of the Moderna vaccine just four hours apart. Following the jabs, the man collapsed after a bout of exhaustion and experienced respiratory issues.

While the man has recovered after 12 days in the hospital, his daughter told Spectrum News 1 he has not been the same since.

“My dad since then has not been aware enough or with it enough for me to be able to say do you remember what happened that day?” she said. “He’s not the same person and it’s pretty disturbing.”

Update 5/14/21, 3:25 p.m. ET: This article was updated as Italian health authorities corrected their statement on the number of doses administered to the woman.