SINGAPORE — The Pfizer’s Comirnaty COVID-19 vaccine has been approved for use in children aged six months through four years in Singapore, making it the second such jab after Moderna's Spikevax to be allowed for inoculating those in the age group.
The Health Sciences Authority (HSA) in a press release on Thursday (29 September) said it carefully considered the clinical data and assessed that the benefits outweighed the risks for the administering of the Comirnaty vaccine to those in the age group.
In making the decision, HSA consulted experts from its medicines advisory committee and panel of infectious diseases experts.
The vaccination regimen for the primary series for children aged six months through four years consists of three three-microgram doses. The first two doses will be administered three weeks apart, followed by a third dose to be administered at least eight weeks after the second dose.
Official vaccination recommendations on the use of this vaccine will be issued by the expert committee on COVID-19 vaccination and the Ministry of Health when ready, said HSA.
The clinical data was based on an ongoing Phase 2/3 study conducted by Pfizer, involving about 1,800 participants aged 6 months through 4 years, according to HSA.
The results showed that the immune response in young children with a three-dose primary series was comparable with that of adults aged 16 to 25 years who had received two higher doses of 30 micrograms as the primary series vaccine.
"Hence, it can be inferred that three doses of the vaccine may provide a similar level of protection in young children as that of two doses in adults," said HSA.
Local real-world data in children aged five to 11 had shown that vaccine effectiveness against the Omicron subvariants was around 40 per cent for symptomatic disease and remained high at more than 80 per cent for protection against COVID-related hospitalisations for children receiving two doses of Pfizer vaccines.
"Hence, it could reasonably be expected that the vaccine would similarly protect younger children aged six months through four years from severe outcomes of COVID-19 such as multisystem inflammatory syndrome (MIS-C) and other potential complications," HSA said.
Preliminary data from a secondary analysis of COVID-19 cases in the clinical study suggests that the vaccine efficacy was about 73 per cent, though HSA noted that the evidence was limited and should be "interpreted with caution".
Safety data from the clinical studies also showed that adverse events in young children were similar to those reported in adults, said HSA. They were mild-to-moderate and commonly reported with childhood vaccination, such as injection site pain, fever, fatigue, and headache.
"These reactions are generally associated with vaccinations and expected as part of the body’s natural response to build immunity against COVID-19. They usually resolve on their own within a few days," said HSA.
While there were no cases of serious adverse events reported in the clinical study with Comirnaty, HSA cautioned that caregivers of young children should monitor for signs and symptoms of myocarditis such as chest pain, breathing difficulty. They should also take precautions to minimise rigorous physical activity following vaccination.
HSA will continue to monitor the safety of the vaccine and require Pfizer to submit data from the on-going clinical study to ensure that the benefits of the vaccine continue to outweigh the risks.
As of Tuesday, 93 per cent of Singapore's total population have completed the full vaccination regime for vaccines under the national vaccination programme, while 80 per cent have received their booster shots.
Do you have a story tip? Email: firstname.lastname@example.org.