The Health Ministry (MOH) is investigating the death of a 103-year-old woman who was erroneously given a fourth dose of the Covid-19 vaccine by a mobile vaccination team.

The woman, a nursing home resident, was admitted to Changi General Hospital on Dec 16 — three days after receiving the extra dose.

She had pneumonia and low sodium levels, and was subsequently diagnosed as having had a stroke.

The woman died on Jan 10.

An autopsy found that the main cause of death was pneumonia, with other contributing factors, including stroke and coronary artery disease. The coroner has not determined if these were linked to vaccination.

However, these are natural disease processes common in seniors, said MOH in a statement on Friday (Feb 4).

MOH said it takes a serious view of the incident and is carrying out a thorough investigation, which is likely to be completed this month.

"Our preliminary findings were that the vaccine was erroneously administered due to possible irregularities in vaccination procedures and poor communication between the nursing home and the medical service provider handling the vaccination," it added.

The woman was a resident at Econ Healthcare's Chai Chee nursing home, while the vaccination was administered by a team from PanCare Medical Clinic.

Both have co-funded the woman's hospital bill as a gesture of goodwill, MOH said.

The ministry added that this is the first case of mistaken identity leading to erroneous vaccination by a mobile vaccination team.

Some 152,000 such mobile vaccinations have been carried out to date.

MOH added that it had originally planned to announce the incident in December.

However, the woman's family had requested to withhold details that could have led to her identification.

"We have since consulted the family further and are releasing the information to provide clarity on the incident."

Both the nursing home and the mobile vaccination provider have reviewed their processes to prevent such an incident from recurring.

A spokesman for Econ Healthcare Group said the mistake was discovered about five minutes after the shot had been administered.

Teams from both Econ and PanCare attended to the woman and extended the time she was under observation for. 

“The resident had no adverse reaction during that time,” the spokesman added.

The Agency for Integrated Care, which facilitates vaccinations in nursing homes, has also reminded the homes to ensure proper communication with mobile vaccination teams.

"MOH has also reminded all mobile vaccination teams to perform independent identity verification and authentication before administering any vaccination," the ministry said.

This article was first published in The Straits Times. Permission required for reproduction.