Why are children hit harder by the Omicron variant of Covid-19?

While several countries are seeing more children hospitalised, the general consensus among experts is that infected children do not fall severely ill. PHOTO: ST FILE

SINGAPORE - The onset of Singapore's Omicron wave has resulted in an uptick in Covid-19 infections among children.

But why is this happening only now?

One reason is that the Omicron variant is better able to resist children's innate immune response, which protected them during earlier waves, said infectious diseases expert Dale Fisher.

In contrast to the Delta variant - which is more likely to infect the lungs - the Omicron variant tends to affect the upper airways.

"These airways and nasal passages are smaller in children, making the risk of symptoms greater," said Professor Fisher, a senior infectious diseases consultant at the National University Hospital (NUH).

"And this could turn into croup or asthma-type syndromes, due to the inflammation and mucous plugging."

While several countries - including the United States - are seeing more children hospitalised, the general consensus among experts is that infected children do not fall severely ill.

One US study found that children under age five who contracted Omicron tended to fare better than those who had been infected by the Delta variant. Such children had a 67 per cent lower risk of being hospitalised and 68 per cent lower risk of being admitted to intensive care.

The study was posted online ahead of peer review in late January, with its authors suggesting that the greater transmissibility of Omicron may still result in overall higher numbers of children requiring hospital care than they did during the Delta wave.

On Sunday (Feb 13), Singapore reported 9,420 new Covid-19 cases, the bulk of whom were adults aged 20 and older.

But 1,130 were children under 12. A total of 56 children in this age group are currently hospitalised, although none requires intensive care or oxygen supplementation.

Last Tuesday, Health Minister Ong Ye Kung said children under 12 have the highest infection rate among all age groups here, at about 67 per 100,000 population.

Those aged 12 to 19 came next, with an infection rate of about 55 per 100,000 population.

Fortunately, said Mr Ong, hospitalisation of children due to Covid-19 is often precautionary in nature, with short stays of two to three days.

But it is still important to make sure there are sufficient paediatric beds available, he added.

Singapore has two public hospitals - NUH and KK Women's and Children's Hospital (KKH) - that are able to deliver specialised medical care for children.

In response to queries from The Straits Times, both hospitals said they are working to increase capacity ahead of a potential spike in paediatric cases.

Professor Lee Yung Seng, who heads the Khoo Teck Puat-National University Children's Medical Institute at NUH, said his hospital's children emergency department is prepared for a sudden surge.

It has beefed up manpower by redeploying staff and tapping employees from the medical institute. "The team is also taking on extra shifts internally to augment shortfalls where needed," Prof Lee added.

The medical institute's inpatient ward has augmented its resources to deal with more young Covid-19 patients.

Associate Professor Chan Yoke Hwee, who chairs KKH's medicine division, said her hospital is working with the Health Ministry to boost national capacity for paediatric patients.

"Plans are in place to accommodate increases in patient cases if needed, and patients will be provided care in a timely manner as appropriate to their acute clinical needs," she added. She noted that the hospital continues to have the capacity to deliver a wide range of clinical services.

In community treatment facilities - which typically take in patients who require closer supervision - bed spaces are being ramped up.

Raffles Medical Group, which operates such a facility at Singapore Expo, said it will be adding another 350 beds.

This brings its total to more than 1,650 beds for patients young and old.

Adjoining rooms are also available for families of up to five people, a spokesman said.

More than 192,000 children aged five to 11 have already received their first dose of the Covid-19 vaccine as at Feb 4.

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