Singapore approves Pfizer Covid-19 vaccine for children aged 6 months to 4 years

SINGAPORE – The Health Sciences Authority (HSA) has approved Pfizer’s Comirnaty Covid-19 vaccine for children aged six months to four years, making it the second vaccine authorized for this age group in Singapore after Moderna’s Spikevax.

In a statement released on Thursday, HSA said that after reviewing clinical data, the benefits of vaccinating young children outweighed the risks. The vaccination regimen consists of three doses of 3 micrograms. The first two doses are given three weeks apart, followed by a third dose at least eight weeks after the second.

HSA emphasized that official recommendations for the use of the vaccine will be made by the Expert Committee on Covid-19 Vaccination and the Ministry of Health. The decision to authorize the vaccine followed consultations with experts from the Medicines Advisory Committee and the Panel of Infectious Diseases Experts.

The clinical data considered by HSA included results from an ongoing Phase 2/3 study by Pfizer, involving around 1,800 children aged six months to four years. The results showed that the immune response in these young children was comparable to that of adults aged 16 to 25, who received a higher dose of 30 micrograms. This suggests that the vaccine could provide similar protection against Covid-19 in young children as it does in adults.

HSA also cited local real-world data showing that Pfizer’s vaccine offers around 40% effectiveness against symptomatic disease caused by the Omicron variant and over 80% protection against Covid-19-related hospitalizations in children aged 5 to 11. It is expected that similar protection will be offered to younger children from severe outcomes such as multisystem inflammatory syndrome (MIS-C) and other complications.

While initial analysis suggests a vaccine efficacy of approximately 73%, the HSA cautioned that this data is limited and should be interpreted with care.

Regarding safety, the study showed that adverse events in young children were generally mild to moderate and similar to those seen in adults, including pain at the injection site, fever, fatigue, and headaches. These side effects are common with vaccinations and typically resolve on their own within a few days.

No serious side effects such as myocarditis (inflammation of the heart muscle) were reported in the study. However, the HSA advised caregivers to be vigilant for symptoms of myocarditis, such as chest pain or difficulty breathing, and to minimize rigorous physical activity after vaccination.

HSA will continue to monitor the vaccine’s safety and require Pfizer to submit ongoing clinical study data to ensure the benefits of vaccination continue to outweigh the risks.