SINGAPORE: Receiving more than the recommended dose of the Pfizer-BioNTech COVID-19 vaccine is unlikely to be harmful, said Singapore's Ministry of Health (MOH) on Saturday (Feb 6), citing clinical trial data from the two pharmaceutical companies.
This comes after an employee from the Singapore National Eye Centre (SNEC) was wrongly administered the equivalent of five doses of the vaccine due to a human error.
The recommended schedule for the Pfizer-BioNTech vaccine is two doses, 21 days apart.
“Clinical trial data from Pfizer-BioNTech has indicated that receiving more than the recommended dose of the Pfizer-BioNTech COVID-19 vaccine is unlikely to be harmful,” said MOH in response to CNA’s queries.
“The affected staff is well, and did not have any adverse reaction or side effects.”
MOH said the incident at SNEC is an isolated one due to a human error by a staff member administering the vaccine, adding that it has not been notified of any similar incidents at other vaccination sites.
The error happened on Jan 14 during a vaccination exercise conducted at SNEC for its staff members.
According to SNEC in an earlier media release, investigations showed that the error resulted from a lapse in communication among the vaccination team at the time.
“The staff in charge of diluting the vaccine had been called away to attend to other matters during the preparation of the vaccine, and a second staff member had mistaken the undiluted dose in the vial to be ready for administering,” said SNEC.
The error was discovered within minutes of the vaccination when the affected employee was resting in a designated area after the jab. As a precaution, the affected employee was warded at Singapore General Hospital (SGH) for observation and was discharged two days later.
AFFECTED STAFF SCHEDULED FOR SECOND DOSAGE PENDING TEST RESULTS
In response to CNA's queries, the eye centre said the affected employee remains well and is scheduled for the second dosage of the vaccine, pending the blood serology test results.
"We will continue to monitor the staff’s health closely and provide the necessary support to the staff and family. The staff is currently well and back to work," it said.
On why it made the error public more than three weeks after the incident, SNEC said: "Our immediate priority is the well-being of the affected staff. We were focused on ensuring that the staff remains well, with no adverse reaction or side effects. We also wanted to respect the privacy of the staff and the staff’s family members."
It added that after the vaccination exercise at SNEC was immediately suspended, it focused on investigations and putting in place measures to ensure that such lapses do not happen again.
"In the meantime, we kept the Ministry of Health informed on the health of the staff and on our investigation," said SNEC.
The employee responsible for administering the erroneous injection has been counselled, it added.
MOH said there are “robust medical protocols in place” at all COVID-19 vaccination sites to ensure the safety of people who received the jab.
“These include protocols for vaccination processes on dose preparation, dilution and vaccine administration, including the need for clear indication to differentiate diluted and undiluted vaccine vials,” said the ministry.
“Following the incident, we have reminded vaccination providers to adhere strictly to the protocols,” it added.
“The safety and health of those receiving the vaccine are our top priority. MOH will continue to work with vaccination providers to ensure the utmost safety in the vaccination process.”