How does the Delta strain affect children?

Madison Oei, 10, plays with her dog Taffy as her brother Izaac, 12, jumps on the trampoline. Picture: Elesa Kurtz
Madison Oei, 10, plays with her dog Taffy as her brother Izaac, 12, jumps on the trampoline. Picture: Elesa Kurtz

As lockdowns drag on and authorities work on plans to bring children safely back to school, there's a growing body of evidence about how the Delta variant is affecting children and adolescents.

Here's what we know at the moment.

Are children more affected by the Delta variant?

The current evidence shows the Delta strain does not appear to cause more severe disease compared to previous variants, but it is more infectious so the number of children who do develop severe symptoms is greater.

Coupled with the fact the vaccine rollout started with older adults and is only now opening up to children aged 12 and above, we are seeing more cases in children and adolescents.

However, they are not getting sicker because of Delta.

A study by the National Centre for Immunisation Research and Surveillance looked at the cases based in schools in greater Sydney from June 16 to July 31. It found most children in the study had no or only mild symptoms of COVID-19.

A research brief published by the Murdoch Children's Research Institute (MCRI) this week said the global data showed the Delta variant did not cause more severe illness in children.

Professor Andrew Steer is the director of the infection and immunity theme at the institute and a paediatric infectious disease physician at the Royal Children's Hospital in Melbourne.


He said less than 2 per cent of children with COVID-19 were admitted to hospital, however, some demographics were at greater risk than others.

"We are seeing a number of groups who appear to be at greater risk and they are children living with disadvantage or in low socioeconomic status, and those with pre-existing health conditions. And we are seeing that those with pre-existing health conditions are more likely to become more unwell," Prof Steer said.

"But stepping back from all that is just to reiterate that, overall, amongst all children COVID-19 infection with the Delta variant is generally very mild or many have no symptoms."

In Australia, no child under the age of 10 has died from COVID-19 and one adolescent has died who had another serious infection in addition to COVID-19.

Are children affected by long COVID?

Children who have had long COVID report fatigue, headache, sore throat and a persisting loss of sense of smell for a period of time after their infection.

However, there is no consistent definition of long COVID and more robust research needs to be done.

A MCRI review published in the Pediatric Infectious Disease Journal found long COVID rarely lasted more than 12 weeks in children and adolescents.

Prof Steer said some studies did not include a control group and the studies which did included one which showed children and adolescents who had other viral infections had similar symptoms.

"Fatigue and those sort of non-specific symptoms can also be symptoms of being in lockdown in public health restrictions as well. It's tiring for all of us," he said.

One study by the MCRI in Melbourne in 2020 found among 136 children with COVID-19 who presented to hospital, none of the patients experienced symptoms of long COVID.

When will a vaccine for under-12s be ready?

Authorities are waiting for the results of two trials for the Pfizer vaccine and the Moderna vaccine to find out if they were safe and effective in children under 12.

"There's lots of experience in delivering vaccines that are effective and safe for younger children. We just need to have those studies done and to get that experienced to understand what we're doing in Australia," Prof Steer said.

What are the indirect effects of the pandemic on children?

Children are suffering indirectly from the pandemic and health restrictions, too. Being away from school has affected their wellbeing, education and social development.

One OECD study suggested losing one-third of the school year could reduce a student's future income by 3 per cent.

Prof Steer said lockdowns and remote learning impacted most greatly on disadvantaged members of the community.

"Schools are really important place for learning, but also for social development and friendships, also important for parents as well so that they can return to work," he said.

He said it was important to vaccinate teachers, parents and adolescents as quickly as possible so children could get back to face-to-face learning.

"I'm not a decision-maker but the important considerations here are balancing the severity of the disease in kids, which is overwhelmingly mild, versus getting kids back to school as safely and as soon as possible," Prof Steer said.

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This story How does the Delta strain affect children? first appeared on The Canberra Times.