157 suspected serious reactions to Covid-19 jabs out of 3.7 million doses in Singapore
There have been 157 reports here of suspected reactions to the Covid-19 vaccines severe enough to be life-threatening or result in hospitalisation, among other serious conditions.
However, no deaths have been linked to the jab, the Health Sciences Authority (HSA) said on Friday.
These "suspected serious adverse events" made up 0.004 per cent of the almost 3.7 million doses of Pfizer-BioNTech and Moderna jabs administered till May 23.
These serious cases form part of the 4,704 "suspected adverse event reports" that HSA received till May 23.
These translate into 0.13 per cent of administered doses, consistent with the percentage that had been reported by the authority on May 6, when it last gave an update on the safety record of both mRNA vaccines.
These reactions are suspected to be associated with the vaccinations but may not have been caused by them.
An adverse event or reaction related to vaccination is any undesirable medical condition that occurs after taking the vaccine, which does not necessarily have a direct link to the treatment.
They may be coincidental or related to an undiagnosed disease but have to be reported by healthcare providers to HSA.
Reactions are considered serious if they result in hospitalisation, disability or life-threatening illnesses, among other things.
Anaphylaxis, which is the rapid onset of severe allergic reactions, was the most frequently reported serious adverse event, with 26 such cases.
All of them recovered after medical treatment, HSA said.
It added that the incidence rate of anaphylaxis reported here with the Pfizer-BioNTech and Moderna vaccines is about 0.85 cases for every 100,000 doses administered.
"This is similar to the incidence rates reported overseas of around 0.5 to two per 100,000 doses administered," said HSA.
Other severe allergic reactions numbered 23.
These include breathing difficulty, fast heart rate, an increase or decrease in blood pressure, chest discomfort and pain, fainting, limb numbness and weakness or pain, change in vision, increase in liver enzymes, joint pain, fits, ringing in the ears and infection.
The authority said most of those who had developed serious adverse events have recovered or are recovering.
"These serious adverse events are being closely monitored by HSA," it added.
HSA said the most commonly reported reactions are consistent with those typically observed following vaccination.
From the 4,704 reactions, the most common one was cases of rash, which accounted for more than one in four reported adverse events.
This was followed by cases of swelling of eyelids, face or lips, which occurred in about one in seven cases.
These are typically resolved within a few days and are in line with the events described in the vaccines' product information, as well as those reported overseas.