Learn about the virus and the vaccines


COVID-19 is caused by the SARS-CoV-2 virus. There have been millions of confirmed cases of COVID-19 in Australia, including hundreds of thousands of children.1 Thousands of people have lost their lives, including children.1 Most children who catch COVID-19 will get better; however, some children get so sick they need to go to hospital or be cared for by hospital staff in a 'hospital at home' program. Children with existing health issues are more likely to require hospitalisation. 

  • What is COVID-19?

    Coronavirus disease 19 (COVID-19) was found in humans in December 2019 and was declared a worldwide pandemic by the World Health Organization (WHO) in March 2020.

    It spreads easily and can be passed from person to person through coughing, sneezing, speaking, singing or breathing, or after touching contaminated surfaces or objects.2

    People usually start to feel unwell about five to six days after they get COVID-19,3 but it can be anywhere from one to 14 days.3 The most common signs of illness are headache, sore throat, cough, runny nose and fever.4

    A number of different versions or 'variants' of COVID-19 have emerged since the virus was first detected. These include Delta and Omicron. The vaccines available in Australia all offer protection against COVID-19 variants.

  • What are the risks of COVID-19?

    COVID-19 has killed thousands of children and adolescents around the world. Most children get better without needing medical help. However, some children have more serious disease and may need to go to hospital for treatments such as oxygen or ventilation (where a machine helps you breathe).

    Two rare but serious longer term problems can happen after infection. 

    The first condition is called multi-system inflammatory syndrome in children (MIS-C). It occurs two to six weeks after COVID-19 infection6 and it causes multiple organs of the body to become inflamed. Organs may include the brain, heart, kidneys, lungs and digestive system.6 Children with this condition can become very sick and often need treatment in an intensive care unit. MIS-C is also sometimes called paediatric inflammatory multisystem syndrome-temporally associated with SARS-CoV-2 (PIMS-TS).

    The second condition is often called ‘long COVID’.7 Some children with COVID-19 will still have symptoms of illness for many months after infection, including headache, fatigue, sleep problems and difficulty concentrating.7,8 The research is still evolving about 'long COVID' in children.

COVID-19 vaccination

COVID-19 vaccines train our bodies to recognise and fight the virus. They do this by teaching our immune system to read the genetic code for an important part of the virus, called the spike protein. 

Vaccination means your child will be less likely to catch COVID-19 and pass it on to others. There is still a small chance that they will catch the virus, but if they do, their symptoms will usually be mild.

Australia is likely to get different COVID-19 vaccines over time. 

The vaccines currently approved for children in Australia are: 

  • Pfizer/BioNTech (Comirnaty) 
  • Moderna (Spikevax) 
  • How do the COVID-19 vaccines work?

    The vaccines contain the genetic code for an important part of the COVID-19 virus called the spike protein. Spike proteins are found on the outside of the virus. Their job is to fuse to the outside of cells, so the virus can enter your cells and cause illness.

    When your child has the vaccine, their body reads this genetic code and trains their immune system to recognise the spike proteins and fight the virus. Within about two weeks of vaccination, their body will start making antibodies. After that, if they come into contact with the COVID-19 virus, these antibodies will attach themselves to the virus and help get rid of it. 

    Your child cannot catch COVID-19 from the vaccines because they don't contain the virus. They only contain the genetic code required to train your immune system to recognise and fight it.

    Different vaccines work with the genetic code in different ways. 

    mRNA vaccines use a piece of code that has been genetically engineered. Australian health authorities have approved the use of the following mRNA vaccines: 

    • Pfizer/BioNTech (Comirnaty) 
    • Moderna (Spikevax) 
  • How were the COVID-19 vaccines tested?

    Safety research is a key part of making vaccines. Vaccines are tested extensively before they are ready for use. Testing begins with research in a lab (test tubes), then animal studies and finally studies in humans (clinical trials), starting with adults and then children.

    Clinical trials involve testing the vaccine in volunteers, and run in three main phases:

    Phase 1 clinical trials usually involve a few dozen healthy volunteers. These trials focus on vaccine safety and finding out if the vaccine causes an immune response.

    Phase 2 clinical trials are bigger and have hundreds of volunteers. These trials test the immune response of the vaccine among a larger group of people, and assess whether it is safe, with acceptable side effects. 

    Phase 3 clinical trials involve many thousands of participants. These trials assess how effective the vaccine is at preventing people from getting the disease. Phase 3 trials can more thoroughly assess the vaccine for safety and side effects. In a Phase 3 trial, researchers usually compare people who received the vaccine with people who didn’t.  
    Typically, these phases happen one after the other. For the development of the COVID-19 vaccines, some of the phases overlapped. For example, Phase 3 studies were started as soon as early data from Phase 1 and 2 trials became available. This approach meant the COVID-19 vaccines could be developed quickly, making them available to save lives sooner.

  • What are the benefits of a COVID-19 vaccine for your child?

    Having the vaccine means your child will be less likely to catch COVID-19 and pass it on to others. If they’re vaccinated, they will be able to visit vulnerable or older family members more safely. Schools will also be safer.

    There is still a chance that your child will catch COVID-19, but if they do, they are likely to have no symptoms or mild symptoms.

    If you want to know more about the benefits of vaccination for yourself, an older teenager or another adult, we recommend that you use the COVID-19 Decision Aid (16+ years).

  • What are the risks of a COVID-19 vaccine for your child?

    Most children and adolescents have mild symptoms for a day or two after a COVID-19 vaccine. This is completely normal and may include pain or tenderness at the injection site, headache, tiredness, chills, and muscle or joint pain.9 Serious side effects are very rare. We will provide more detail about the risks of vaccination side effects in the next steps of this decision aid. 

    You may have heard people talk about other risks associated with COVID-19 vaccines. These are not mentioned here because there is no scientific evidence to support them. You may also have heard the misinformation that COVID-19 vaccines contain aborted foetal cells. This is not true, and religious communities including the Greek Orthodox Church of Australia have encouraged the use of COVID-19 vaccines.

    If you want to know more about the risks of vaccination for yourself, an older teenager or another adult, we recommend that you use the COVID-19 Decision Aid (16+ years).

  • Do the vaccines work for different variants?

    Yes. The currently approved vaccines are highly effective against existing variants. There is still a chance that your child will catch COVID-19, but if your vaccinations are up to date, their illness will not be severe.

  • If my child has had COVID-19, do they still need the vaccine and boosters?

    Yes. If your child has tested positive to COVID-19, their chance of reinfection will be reduced, but only for a few months. 

    Making sure your child is up to date with their vaccinations is the best way to keep them protected against the virus. It is recommended that they complete their vaccination within four months of recovering from acute illness.

+ References

  1. Australian Government Department of Health. Coronavirus (COVID-19) case numbers and statistics; Available from: https://www.health.gov.au/health-alerts/covid-19/case-numbers-and-statistics#at-a-glance Accessed February 2022.
  2. World Health Organization. Transmission of SARS-CoV-2: implications for infection prevention precautions. Scientific brief. [Internet.] Geneva: WHO; 9 July 2020. Available from: https://www.who.int/news-room/commentaries/detail/transmission-of-sars-cov-2-implications-for-infection-prevention-precautions
  3. McAloon C, Collins Á, Hunt K, Barber A, Byrne AW, Butler F et al. Incubation period of COVID-19: a rapid systematic review and meta-analysis of observational research. BMJ Open. 2020;10(8). doi: https://doi.org/10.1136/bmjopen-2020-039652
  4. Zoe COVID Study. What are the top 5 COVID symptoms? 2021. Available from: https://covid.joinzoe.com/post/new-top-5-covid-symptoms#part_3 
  5. Rothan HA, Byrareddy SN. The epidemiology and pathogenesis of coronavirus disease (COVID-19) outbreak. J Autoimmun. 2020;109. doi: https://doi.org/10.1016/j.jaut.2020.102433  
  6. BMJ: Best Practice. Coronavirus disease 2019 (COVID-19). Available from: https://www.kff.org/coronavirus-covid-19/issue-brief/update-on-covid-19-vaccination-of-5-11-year-olds-in-the-u-s/ 
  7. Zimmermann P, Pittet LF, Curtis N. How Common is Long COVID in Children and Adolescents?, The Pediatric Infectious Disease Journal: December 2021 - Volume 40 - Issue 12 - p e482-e487 doi: 10.1097/INF.0000000000003328 
  8. Borch L, Holm M, Knudsen M et al. Long COVID symptoms and duration in SARS-CoV-2 positive children — a nationwide cohort study. European Journal of Pediatrics (2022). https://doi.org/10.1007/s00431-021-04345-z
  9. National Centre for Immunisation Research and Surveillance. AusVaxSafety. 2022. https://www.ausvaxsafety.org.au/ accessed February 2022.