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How does the coronavirus vaccine work?

Clare Armstrong and Donna Coutts, February 16, 2021 6:45PM Kids News

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Pfizer vaccine arrives into Sydney International Airport on Singapore Airlines, February 15. Picture: Adam Taylor/PMO media_cameraPfizer vaccine arrives into Sydney International Airport on Singapore Airlines, February 15. Picture: Adam Taylor/PMO


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In less than one week a group of Australian quarantine and healthcare workers will receive their first dose of the Pfizer COVID-19 vaccine.

More than 142,000 doses of Pfizer vaccine arrived at Sydney Airport shortly after midday on Monday.

The precious cargo was taken to a secure location for the vaccine to be quality checked.

About 62,000 doses will be kept aside in case there is a problem with future supply so people are able to receive the second required dose in the correct time frame.

Of the remaining 80,000, about 50,000 will be distributed evenly among the states according to population. The states will then start to vaccinate priority quarantine, frontline health, disability and aged care workers.

It is expected the initial fortnight of the rollout will focus on hotel quarantine workers, who have become a major source of risk for COVID-19 outbreaks in the community.

The federal government will keep back about 30,000 doses to be distributed to aged care facilities.

Health Minister Greg Hunt announced the historic moment by declaring “the eagle has landed” and confirmed February 22 would be the start date of the rollout.

Prime Minister Scott Morrison will be given the Pfizer vaccine in the first batch of doses.

The Australian government has promised COVID-19 vaccines will be voluntary and free.

A vaccine is a medicine that trains the body’s immune system to fight off a disease it may be exposed to in the future. They’re preventative, rather than a treatment for a disease you already have. Most vaccines are given by injection into a muscle, such as in your arm, though some can be given as a medicine you drink.

Our immune system is like a library of billions of different disease-fighting white blood cells. When a bacteria or a virus gets into our body, the immune system chooses a type of white blood cell from its library that makes a particular antibody* to perfectly match the shape of the invading bacteria or virus and lock into it to take it out of action.

For most bacteria and viruses circulating around the world, this works pretty well, but it can take a few days for your body to make enough antibodies to fight off the invaders, in which time you could already be getting really sick.

A vaccine gives your immune system a head start to prepare its defences. Vaccines deliver dead or weakened bacteria or virus cells, or even just a tiny piece of a bacteria or virus cell, such as a piece of genetic code, to tell your immune system to get to work making antibodies to fight off the invaders.

Some vaccines work best if two or more doses are given either weeks or months apart, giving the immune system more time and more practise at getting ready to fight off the real thing.

In the future, if the real bacteria or virus gets into your body, your immune system remembers what to do from its earlier training and can get ahead of the bacteria or virus trying to multiply in your body.

media_cameraAn artist’s impression of a coronavirus cell. The genetic code delivered by the Pfizer vaccine tells the body’s cells to start making the spike proteins like those on the outside of the coronavirus cell.

The Pfizer vaccine is called an RNA or mRNA vaccine. The m stands for messenger, which means it delivers a tiny piece of the coronavirus’ genetic code (a message) when it is injected into the body. The piece of genetic code is encased in a bubble of fat.

The genetic code tells the body’s cells to start making the spike proteins on the outside of the coronavirus. The body’s immune system detects the spike proteins and starts making antibodies to destroy cells that contain the spike proteins.

If you are exposed to the actual coronavirus in the future, your body will know what to do.

The Pfizer vaccine is designed to be given in two injections, 21 days apart.

President-Elect Biden And Vice President-Elect Harris Receive Second Round Of COVID-19 Vaccination media_cameraPresident Joe Biden receives the second dose of the Pfizer COVID-19 vaccination on January 11 in Newark, Delaware, US, three weeks after the first dose he had received a few days before Christmas in 2020. Picture: Getty Images/AFP

The Pfizer vaccine needs to be kept really, really cold — minus 70C to keep it stable. (The average winter temperature at the South Pole on Antarctica is minus 49C, with the lowest temperature ever recorded there minus 89.6C.

Keeping a vaccine so cold requires it to be transported in dry ice* in special freezers.

There’s been a lot in the news in past weeks about new variants or mutations* of the coronavirus — such as the “UK strain” or the “South African strain”, meaning the genetic code of the virus is changing or evolving as it moves through the population.

Trials so far show that the current vaccine is able to respond to a variety of mutations. Scientists will continue checking that it keeps working as the coronavirus changes.

The Pfizer vaccine is just one vaccine being used in other countries to protect people against developing COVID-19.

The other two vaccines most likely to be used in Australia in the near future are the Oxford/AstraZeneca and Novavax vaccines.

Australia’s Therapeutic Goods Administration (TGA) — a group of experts who decide whether vaccines are safe and effective — announced on Tuesday afternoon it had granted provisional approval for the Oxford/AstraZeneca vaccine to be used in Australia. This vaccine could be made in Australia in the future rather than needing to be brought in from another country.

Health Minister Greg Hunt said TGA approval of the AstraZeneca vaccine would mean “a doubling of the number of doses per week by early March, if not earlier.”

Australia’s leaders will roll up their sleeves for a mix of the available COVID-19 vaccines in Australia to show their confidence in the vaccines.

Mr Hunt and Health Department Secretary Professor Brendan Murphy will be given the AstraZeneca vaccine.

Chief Medical Officer Professor Paul Kelly said he was not yet sure which vaccine he would be provided but he would be glad to receive either.


  • antibody: Y-shaped proteins that attach to bacteria or virus cells that invade the body; they then signal to the body’s immune system to start work
  • dry ice: cooled and condensed carbon dioxide, which is much colder than ice made from water
  • mutations: a change in the arrangement or sequence of genes


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  1. What is a vaccine?
  2. Do you have a vaccine before you get sick or after, to make you better?
  3. What is in the Pfizer vaccine?
  4. Which groups of people will get the vaccine first?
  5. Why will Australia’s leaders get a mix of the different vaccines?


1. Vaccine For and Against
These newly developed COVID-19 vaccines are hopefully going to allow our country to eradicate the coronavirus so we can go back to living our normal lives. However, it’s not compulsory that everyone gets the vaccine and for some people, it is not recommended (such as pregnant women). Therefore, if not everyone is receiving the vaccine, there’s a possibility that the virus could still be in the community.

Work with a classmate and complete the table below on reasons why you should get the vaccine if you can, and reasons why people might not want the vaccine. This could also apply to other vaccines such as the flu, measles and mumps vaccines that both children and adults are advised to get.

Use a table like this to record your answers media_cameraUse a table like this to record your answers

If you are healthy enough to receive the vaccine, do you think you should have to get it? Why/why not?

Time: allow 25 minutes to complete this activity
Curriculum Links: English, Science, Critical and creative thinking, Ethical understanding

2. Extension
If all three vaccines are approved and ready to be distributed to the public, which brand would you choose? Justify your reasons.

Do a poll of your classmates to see which one they would choose and why.

Time: allow 15 minutes to complete this activity
Curriculum Links: English, Science, Ethical, Critical and creative thinking

Proper Noun Police
A proper noun is a noun that names a particular person, place or thing. It always has a capital letter.

How many proper nouns can you find within this article? Find them all and sort them into the category of name, place, time (date/month).

Can you find any proper nouns included in your writing?

What are they?

Can you sort them into their categories?

HAVE YOUR SAY: How do you feel about getting a coronavirus vaccine?
No one-word answers. Use full sentences to explain your thinking. No comments will be published until approved by editors.

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