10 cases of serious side effects from Covid-19 vaccines reported among children aged 5 to 11: HSA

SINGAPORE — Ten cases of "serious adverse events" due to the Covid-19 vaccination had been reported among children aged five to 11 as of Jan 31, the Health Sciences Authority (HSA) said on Wednesday (Feb 23), the first time that these have been reported among the age group.

These effects included seizures (fits), appendicitis, drop in blood pressure, allergic reaction, abnormal renal function and swelling of small blood vessels. 

The 10 are among 280 reports of adverse events among this age group, representing 0.12 per cent of the 238,253 doses administered. 

In its 10th safety report on the Covid-19 vaccination exercise, HSA said that the reporting rates of serious adverse events in children is similar to that observed in adolescents and adults at 0.004 per cent of administered doses. 

An adverse event is any undesirable medical condition that occurs after vaccination and does not necessarily mean that the vaccine caused it. These have to be reported by healthcare providers to HSA. 

Serious adverse events may result in hospitalisations, a significant reduction in functioning level, a life-threatening illness, a birth defect or death.

“HSA is closely monitoring the adverse events reported in children and is assessing them in the context of background incidence rates,” it said. 

COMMON ADVERSE EVENTS

As of Jan 31, 12,755,259 doses of the Pfizer-BioNTech and Moderna messenger ribonucleic acid (mRNA) vaccines have been administered across Singapore.

Of this number, HSA received 15,655 adverse event reports, which made up 0.12 per cent of the doses administered. 

The most commonly reported ones included allergic reactions, dizziness, shortness of breath, chest discomfort or pain, palpitations, fever, headache, muscle aches, and pain and swelling at the injection site. 

These reported effects generally resolved within a few days, HSA noted. 

Of the 15,655 suspected adverse event reports received for the mRNA vaccines, 820 — or 0.006 per cent — of the reports were assessed as serious. 

The most frequently reported ones were anaphylaxis, which is a potentially life-threatening allergic reaction, as well as other severe allergic reactions such as rheumatoid arthritis, chest pain and nerve damage. 

ADVERSE EVENTS WITH BOOSTER DOSES

A total of 3,194,494 people have received their vaccine booster as of Jan 31, since the national Covid-19 booster vaccination programme was rolled out on Sept 15 last year. 

There were 553 adverse event reports associated with the use of the Pfizer-BioNTech vaccine and 289 adverse event reports with the Moderna vaccine as booster doses.

There were 73 cases of serious adverse events reported, making up 0.002 per cent of administered doses. Fifteen of these cases were myocarditis (inflammation of the heart muscle) and pericarditis (inflammation of the membrane around the heart). 

“Overall, the adverse event reports with the booster doses described similar adverse events associated with Dose 1 and Dose 2 of the mRNA vaccines and there was no observed increase in frequency,” HSA added. 

SINOVAC AND SINOPHARM

Out of 369,083 Sinovac vaccine doses administered here so far, there have been 299 reports of adverse events.

This made up 0.08 per cent of the doses administered. 

The commonly reported ones were rash, hives, angioedema (swelling of the deeper layers of the skin), shortness of breath, chest discomfort and dizziness. 

There were 22 serious adverse events, which made up 0.006 per cent of all administered doses of Sinovac were reported.

This included 12 cases of anaphylaxis, which HSA said "had occurred in individuals who had previous allergic reactions with the mRNA vaccines or had multiple drug allergies". 

The other reports include Bell’s palsy (temporary weakness or paralysis of the facial muscles), blood clots and numbness. 

The Sinopharm vaccine was rolled out on Aug 30 last year and 89,350 doses were administered as of Jan 31. 

HSA has received 41 suspected adverse event reports, making up 0.05 per cent of doses administered. 

The non-serious ones included rash, angioedema, shortness of breath, numbness, syncope (fainting), chest discomfort and tinnitus. 

There were six serious adverse event reports, including low platelet count, syncope with muscle jerks and frequent palpitations. These made up 0.007 per cent of doses administered.