Explained: Why is Singapore shutting down schools over fears of B.1.617 variant of Covid-19?

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What is the situation in Singapore, and why have authorities taken the decision to shut down all schools? And is the B.1.617 variant affecting more children?

Why did Singapore decide to shut down schools now?

There is no official confirmation at this stage on how many children have been affected by the new variant of Covid in Singapore.

The decision to shut down schools came after the city-state detected 38 locally transmitted Covid cases, with 17 currently unlinked. The 38 locally transmitted cases caused the highest single-day spike since September last year. Among the new infections were four children, related to a cluster in a tuition centre, who tested positive.

“The sharp rise in the number of community cases today requires us to significantly reduce our movements and interactions in the coming days,” Education Minister Chan Chun Sing was quoted as saying by Reuters.

Among the 61,000 Covid cases that Singapore has reported till date, most of the infections were from foreign worker dormitories. The new infections on Sunday were among the highest local cases detected outside dormitories in a year.

Over one-fifth of Singapore’s population has been vaccinated with two doses of Pfizer-BioNTech and Moderna. It now plans to inoculate people below 45 years of age from the second half of May. The country has also approved the Pfizer-BioNTech for children above the age of 12.

People wearing masks cross a road in Singapore. (Reuters Photo)

Singapore has been reporting zero or single-digit infections for months and its number of cases are significantly lower than other countries in Southeast Asia. But after the uptick in cases on Sunday, the government imposed the strictest possible curbs on gathering and other public activities since the lockdown imposed in the country last year.

Is the B.1.617 variant affecting more children?

The B.1.617 variant, which is widely considered to be one of the primary reasons behind the huge surge in number of infections across India during the second wave of the pandemic, has been termed as a ‘global variant of concern’ by WHO. It has already spread to more than 40 countries and several countries have put travel restrictions for passengers coming from India as a result of the surge in cases here.

Though the variant, which has two mutations — E484Q and L452R — in its spike protein, is believed to be driving the Covid surge in India, there is still no definitive evidence to conclude if it is deadlier or is causing a more severe form of infection.

One reason why more children may be getting affected is because the B.1.617 variant has a mutation that makes it easier for the virus to latch onto human cells and cause an infection.

Lab studies have shown that the B.1.617 variant can attach with more strength to the ACE-2 receptors, the site where the coronavirus binds to our cells, than the earlier versions of the virus.

Children generally have underdeveloped sinuses and fewer ACE-2 receptors which protect them from getting infected. A study by The University of Texas Health Science Center at Houston (UTHealth) and Baylor College of Medicine conducted last year stated that Angiotensin-converting enzyme 2s, or ACE-2, are the doors that allow SARS-CoV-2 to enter the body. Since children have less ACE-2 in their lungs, they are less likely to be affected. The paper, which was published in the American Journal of Physiology-Lung Cellular and Molecular Physiology, pointed out only about 1.7% of the first 149,082 cases in the US were infants, children and adolescents younger than 18 years.

An ambulance in front of a dormitory in Singapore (Reuters Photo)

But the B.1.617 variant could have changed that. Scientists say that this variant can possibly attach with more strength to the ACE-2 receptors, which means it can then have less attachment sites and still infect people. This could be one of the reasons why children are more vulnerable to this new variant.

But it is important to understand that there are no reports stating that children are getting sicker and cases of Covid infections are turning more serious in children.

What effect are Covid variants expected to have on children in the future?

Till date, reported deaths due to Covid among children have been considerably low. But Brazil might well be an exception right now. In the South American nation which is ravaged by the pandemic, babies and young children are dying at a disturbingly high rate.

Though official estimates are far more conservative, Dr. Fátima Marinho, an epidemiologist at the University of São Paulo, who is leading a study tallying the death toll among children based on both suspected and confirmed cases, believes that more than 2,200 children under five years of age have died since the start of the pandemic, including more than 1,600 babies less than a year old.

“We are seeing a huge impact on children. It’s a number that’s absurdly high. We haven’t seen this anywhere else in the world,” Dr Marinho was quoted as saying by The New York Times.

While there is no evidence to suggest if any mutated form of the virus is responsible for the surge in number of deaths among children in Brazil, the P.1 variant, which has spread widely in Brazil, appears to be leading to higher death rates among pregnant women. Many women with Covid are reportedly giving birth to stillborn or premature babies already infected with the virus.

Experts, however, say the rising number of infections and deaths among children in Brazil might also be due to President Bolsonaro’s cavalier attitude and botched response to the pandemic, lower testing rates and lack of adequate access to medical attention at the right time.

A study published in the Pediatric Infectious Disease Journal in January found that children in Brazil, Mexico, Colombia, Peru and Costa Rica developed more severe forms of Covid-19 and more cases of multisystem inflammatory syndrome, a rare and extreme immune response to Covid-19.

Some top virologists have pointed out that third wave of the pandemic in India may affect children more. As vaccination covers a wider part of the population, children without inoculation may well be among the most vulnerable group. Others have, however, argued that there is no compelling evidence to arrive at the conclusion.

The US FDA has given emergency use authorisation to the Pfizer-BioNTech vaccine for children above 12 years. In India, until we have approval for a Covid vaccine for children, administering the shot to as many parents of young children as possible may well be our best bet.