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The secret to why children are better at fighting off Covid-19

Sue Dunlevy, February 23, 2022 6:30PM Kids News

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New research findings suggest adults produce four times the volume of droplets compared to children during activities like singing, which is great news for school choirs. Picture: AAP Image media_cameraNew research findings suggest adults produce four times the volume of droplets compared to children during activities like singing, which is great news for school choirs. Picture: AAP Image

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Children are better at fighting off Covid than adults because they have a stronger innate* immune system, a new Yale University study shows.

They also have fewer of the ACE2 receptors* in their bodies than adults, which also makes infection more difficult for the virus, according to Australian National University (ANU) infectious diseases expert Professor Peter Collignon.

The Covid-19 virus binds to these receptors in order to infect our cells.

“One of the main receptors that the Covid virus locks on to is the ACE2 and basically children seem to have a lot less of it at least until puberty*,” Professor Collignon said. “That’s a big factor – and their innate immunity also works differently.”

He said while a small number of children developed bad cases of the virus, most experienced only mild symptoms.

Gap High media_cameraMost cases of Covid-19 among children are mild – and the return to school did not result in a huge spike in cases as feared.

“Everywhere around the world, the peak, the people who get Covid and spread it are 20 to 30-year-olds, and then probably 30 to 40-year-olds, mainly because they interact so much,” he said.

“So it was always ridiculous closing schools, particularly primary schools, when you had … (venues including) restaurants open.”

Professor Kevan Herold, an immunobiology* expert at Yale University, has been examining why children are better at dealing with the virus.

He tested nose and throat swabs from 12 children and 27 adults and found the samples from children contained higher levels of two immune proteins called cytokines than samples from adults.

Also, more genes involved in the initial immune system response to invaders were active in children than in the adults.

QST School Captains feature - generic girl in uniform media_cameraChildren seem to have a lot less of the ACE2 receptors than adults – at least until puberty.

HOW DOES THE IMMUNE SYSTEM WORK?

The human immune system has two lines of defence.

The first line, called the “innate immune system”, is the mucus in the nose and throat that traps harmful particles and keeps them out of the body.

It also involves proteins called cytokines that trigger the body to fight off bugs and this is the system that is stronger in children.

The body’s second line of defence is the “adaptive immune system”, which uses T cells and B cells to fight off an invader.

It remembers past infections and gathers forces to fight them off in the same way it did before and this is the system that is stronger in adults.

It is not as strong in children because they have not had as many infections over their lifetime.

This lack of immune memory could be an advantage for children in fighting off Covid-19, according to Peter Doherty Institute researcher Dr Amy Chung. Children don’t have a strong pre-existing antibody* response, but when they encounter the Covid-19 virus, their immune system attacks the essential parts of the virus immediately.

media_cameraPeter Doherty Institute researcher Dr Amy Chung suggests that the lack of immune memory could be an advantage for children in fighting off Covid-19.

Omicron cases have been in decline nationally after peaking in mid-January and experienced only a tiny increase the week school returned before continuing to decline. New research has found that children also produce fewer aerosol particles – or droplets – than adults when speaking and singing, which may help explain limited transmission since students returned to school.

Elementary school teacher singing with children in the classroom. media_cameraHealth orders have included children’s activities as well, from face-to-face music lessons to children’s choirs.

Scientists measured the emission* rate of 15 preadolescent children while speaking and singing and compared them to 15 adults under the same conditions. The study, published in the Journal of the Royal Society Interface, found that the children’s droplet production was around four times lower than adults.

Indoor public speaking and singing are among activities most restricted since the start of the pandemic. Health orders have included children’s activities as well, from face-to-face music lessons to children’s choirs. But existing risk assessments for children have been based on adult emission measurements – something that could change with these findings. Music to the ears of young performers everywhere.

GLOSSARY

  • innate: natural, inherent, present from birth
  • receptors: cell structures that receive signals and change them into something else
  • puberty: when the body begins to develop and change from child to adult
  • immunobiology: student of immune response and the biology of disease
  • antibody: protective protein produced by the immune system in fight infection
  • emission: the production and release or discharge of something, like saliva

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QUICK QUIZ

  1. Children have fewer of what kind of receptors in their bodies than adults?
  2. What are the two different human immune systems called?
  3. What is the name of the immune proteins used in the Yale study?
  4. Why could having less immune memory be an advantage for children fighting Covid?
  5. Children’s droplet production was how many times lower than adults’?

LISTEN TO THIS STORY

CLASSROOM ACTIVITIES
1. Make a “top five” list
What are the FIVE most important pieces of information in this story? Write a list. Next to each item on your list, write sentences explaining why this information is so important.

Time: allow 25 minutes to complete this activity
Curriculum Links: English; Health and Physical Education; Science

2. Extension
Design a diagram that shows how the human immune system works. Don’t forget that there are two lines of defence!

Time: allow 40 minutes to complete this activity
Curriculum Links: English; Health and Physical Education; Science

VCOP ACTIVITY
Masks for children in Years 3-6
With all the research presented in this article, why will some Australian school students in grades 3-6 still be required to wear a mask when everyone else will have restrictions removed?

Research which states and/or territories will continue to enforce masks for primary school students and write a letter to the leader/s expressing your opinion, whether you agree with the decision for mask restrictions for these students or not.

Whenever you are trying to convince someone of your opinion, you should be emotive to convey your feelings and be persuasive, but respectful so as not to get them off-side.

You should back up any of your opinions with evidence – this might be research from the article or personal experiences.

Remember to organise your work so it is clear. Begin by stating the topic and your opinion in the introduction, outline your arguments before explaining them in detail in each paragraph. Use high level connectives to link your arguments together (furthermore, in addition etc.). Summarise again in your conclusion.

Read your letter aloud in an expressive voice to see how it sounds. Edit and up-level before sharing with the class.

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