COVID-19

What you need to know about COVID-19 to protect yourself, your family, friends and the rest of the community.

Immunisation Coalition

About COVID-19

COVID-19 is a disease caused by a new form of coronavirus, first reported in December 2019. Coronaviruses are a large family of viruses that cause respiratory infections. These can range from the common cold to more serious diseases.

Watch the video on the WHO website

Variants

Covid-19 viruses can mutate (change) themselves when they replicate (make copies of themselves).  Viruses that have mutated in this way are called variants.

There have been many identified SARS-CoV-2 virus variants as the virus mutates and evolves over time. Omicron, a variant of the SARS-CoV-2 virus, was first identified in November 2021 and was officially designated as a variant of concern by the World Health Organization (WHO) shortly thereafter.

Each variant and subvariant is associated with varying levels of transmissibility, immune escape, and disease severity. The latest in Australia being the JN.1 variant.

What’s important is for people to stay vigilant, ensure they are vaccinated against the virus (particularly for at-risk individuals with underlying medical conditions), and continue to apply non-pharmaceutical practices during outbreaks.

COVID-19 Symptoms

Symptoms of COVID-19 can range from mild illness to pneumonia. Some people may get very sick very quickly, and most people will recover easily. People with coronavirus may experience symptoms such as:1

  • Fever
  • Coughing
  • Sore throat
  • Shortness of breath

Other symptoms can include runny nose, acute blocked nose (congestion), headache, muscle or joint pains, nausea, diarrhoea, vomiting, loss of sense of smell, altered sense of taste, loss of appetite and lethargy.2

COVID Symptom and Antiviral Eligibility CheckerIf you are concerned that you, or anyone close to you may have COVID-19 symptoms, you can use the HealthDirect COVID- 19 Symptom and Antiviral Eligibility Checker.

 

 

 

 

COVID-19 SymptomsSymptoms of a ColdSymptoms of Influenza

How COVID-19 Spreads

The virus can spread from person to person through:

  • close contact with an infectious person (including in the 48 hours before they had symptoms)
  • contact with droplets from an infected person’s cough or sneeze
  • touching objects or surfaces (like doorknobs or tables) that have droplets from an infected person, and then touching your mouth or face.

Current evidence suggests that the most likely spread is from respiratory droplets between people from close contact with each other.3, 4

People are believed to be most infectious two days before they start showing symptoms.5 However even if people do not show any symptoms, they can still spread the virus to other people.

Watch the video on the WHO website.

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COVID-19 Complications

Most people will recover from Covid 19 within a few weeks, however it can cause serious complications. Older people and those with underlying medical conditions e.g., heart disease, diabetes, obesity, chronic liver disease, severe asthma and cystic fibrosis may be more likely to develop a more serious illness.6

What causes Covid 19 complications?

Covid 19 complications may be caused by a cytokine storm. Cytokines are inflammatory proteins that can flood the bloodstream after an infection like COVID 19 triggers the immune system. The large influx of cytokines can cause damage to many organs of the body like the heart, lungs, liver and kidneys.7

The most common complications are of the lungs and respiratory system, they are:

  • Pneumonia: an infection that affects one or both lungs. The air sacs in the lungs become inflamed making it harder to breathe. This type of pneumonia may cause scar tissue and long-term damage to the lungs.7
  • Acute Respiratory Distress Syndrome: the lungs become so severely damaged that fluid flows into them which inhibits the body getting oxygen into the bloodstream.7

The other complications may be:

  • Acute liver injury: when the liver suddenly stops working8
  • Acute cardiac injury: damage to the heart8
  • Secondary infection: when the body develops another infection unrelated to Covid-19 e.g., a bacterial infection like Strep or Staph9
  • Acute kidney injury: an abrupt decrease in kidney function10
  • Septic shock: a life-threatening condition when the blood pressure drops to a dangerously low level after an infection11
  • Disseminated intravascular coagulation: the body doesn’t clot properly, forming abnormal clots which can lead to internal bleeding and organ failure12
  • Blood clots: clumping of blood cells in the blood vessels13
  • Multisystem inflammatory syndrome in children: some organs in the body become severely inflamed. Symptoms include fever, belly pain, vomiting, diarrhoea, headache, rash and confusion14
  • Chronic fatigue: Symptoms may include brain fog, severe fatigue, pain, trouble thinking or dizziness15
  • Rhabdomyolysis: muscles break down and tissues die. As the cells break, a protein is released into the bloodstream which if the kidneys can’t clear, it could be fatal16
  • Damage to the brain: even in young people, COVID-19 can cause strokes and Guillain Barre Syndrome.17,18

People with severe symptoms may be hospitalised and treated in the Intensive Care Unit with mechanical devices such as ventilators. Surviving these experiences can make them more likely to suffer from post-traumatic stress disorder, depression and anxiety.19,20,21

Long COVID

WHO defines Long COVID as the continuation or development of new symptoms 3 months after the initial SARS-CoV-2 infection with these symptoms lasting for at least 2 months with no other explanation.22

The symptoms may include fatigue, shortness of breath and cognitive dysfunction.

10–20% of people with over 17 million people across the WHO European Region have experienced Long Covid during the first two years of the pandemic (2020/21).22

In Australia, an AIHW review found that 5–10% of COVID-19 cases reported symptoms persisting for more than 3 months with the vast majority resolving within 12 months.23

The key risk factors include: severe COVID-19 illness, comorbidities, female, mid-adult age groups23

Two COVID-19 vaccination doses are associated with a 13% to 47% lower risk of symptoms persisting beyond 4 weeks.24

The Immunisation Coalition has supported the development of the CoRiCal Long-COVID Calculator which provides a personalised risk assessment of developing long COVID 6 months after infection.

Who is Most at Risk?

You are at a high risk of becoming very sick from COVID-19 and needing hospital treatment, if you:25

  • Are 70 years of age or older
  • Are 50 years of age or older with two risk factors including neurological disease, chronic lung disease (moderate or severe asthma requiring inhaled steroids), heart disease, obesity, diabetes, kidney disease)
  • Are Aboriginal and/or Torres Strait Islander, 30 years of age or older, with one of the risk factors above
  • Are 18 years of age or older, and moderately to severely immunocompromised
  • Live in a rural or remote area with limited access to healthcare
  • Live in a residential aged care facility
  • Have complex and significant disability
  • Are pregnant
  • Are on immunosuppressants
  • Have certain health conditions

Among patients with vaccine breakthrough COVID-19 hospitalisations, 40-44% had immunosuppression.26,27

COVID-19 Prevention

ATAGI recommends a dose of COVID-19 vaccine for adults aged ≥75 years every 6 months.28

ATAGI recommends the following groups receive a dose of COVID-19 vaccine every 12 months, and can consider a dose every 6 months, based on a risk-benefit assessment:

  • Adults aged 65—74 years
  • Adults aged 18—64 years with severe immunocompromise

The following groups can consider a COVID-19 vaccine every 12 months, based on a risk-benefit assessment:

  • All other adults aged 18—64 years
  • Children and adolescents aged 5—<18 years with severe immunocompromise

 

For more information on how these vaccines work see The Different Types of COVID-19 Vaccines article from the WHO.

Watch video on WHO website

 

COVID-19 Treatment

Doctors will need to review patients’ medications and their current medical conditions to decide if a COVID-19 treatment is suitable for them. The types of COVID-19 treatments that are suitable will also depend on the severity of their COVID-19 illness.

Basic in hospital treatment options include: oxygen for severely ill patients, ventilation for patients who are critically ill and the use of Dexamethasone or other corticosteroids. Antivirals, immune modulators and monoclonal antibodies have also been used.

COVID-19 Antiviral Medication

Antiviral medications can help prevent severe COVID-19 if taken within five days of symptom onset.29

There are two COVID-19 oral antiviral treatments available for the treatment of COVID-19:

  • Nirmatrelvir and ritonavir (Paxlovid)
  • Molnupiravir (Lagevrio)

These are available for eligible people who are vulnerable to severe disease such as older people, those with comorbidities, people who are immunosuppressed with a script from a GP.

Paxlovid

Paxlovid has provisional approval for the treatment of coronavirus disease 2019 (COVID-19) in adults 18 years of age and older, who do not require initiation of supplemental oxygen due to COVID-19 and are at increased risk of progression to hospitalisation or death.30

Lagevrio

Lagevrio (molnupiravir) has provisional approval for the treatment of adults with COVID19 who do not require initiation of oxygen due to COVID-19 and who are at increased risk for hospitalisation or death.31

Available on Pharmaceutical Benefits Scheme (PBS):

  • COVID-19 oral antiviral treatments nirmatrelvir and ritonavir (Paxlovid) and molnupiravir (Lagevrio) are available through the PBS for eligible patients.

 

Severity of COVID-19

Mild Illness: Individuals who have any of the various signs and symptoms of COVID-19 (e.g., fever, cough, sore throat, feeling unwell, headache, muscle pain, nausea, vomiting, diarrhea, loss of taste and smell) but who do not have shortness of breath, difficulty breathing or abnormal chest imaging. These individuals do not require oxygen.32

Moderate Illness: Individuals who show evidence of lower respiratory disease (e.g. pneumonia) during clinical assessment or imaging and who have low oxygen levels. These individuals require oxygen. 32

Severe Illness: Individuals who have lower respiratory disease with severely low levels of oxygen in their blood. These individuals require oxygen. 32

Critical Illness: Individuals who have respiratory failure (where the lungs have trouble loading oxygen or removing carbon dioxide), septic shock (blood pressure drops to a dangerously low level after an infection), and/or multiple organ dysfunction. These individuals require oxygen. 32

 

Natural Treatments

Natural treatments such as zinc, melatonin, vitamin C, vitamin D, and other supplements are readily available and commonly used to help prevent or treat COVID-19; however, there is insufficient data to recommend the use of such for the prevention or treatment of COVID-19.

The Immunisation Coalition takes an evidence-based approach to COVID-19 treatment.

More COVID-19 Information

Australian Department of Health: Coronavirus (COVID-19) resources for the general public
ACT Government: COVID-19
Department of Health and Human Services Victoria: Coronavirus (COVID-19)
Coronavirus Victoria: Translated information about COVID-19
Coronavirus Victoria: Symptoms and Risks
Coronavirus Victoria: Education – Information for parents, students and educators
NSW Health: COVID-19 Frequently Asked Questions
Northern Territory Department of Health: Coronavirus
Western Australia: COVID-19 (Coronavirus)
Queensland Health: Coronavirus(COVID-19)

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  3. World Health Organization. Coronavirus disease (COVID-19): How is it transmitted? Accessed 19 October 2022
  4. Brooks JT, Butler JC. Effectiveness of Mask Wearing to Control Community Spread of SARS-CoV-2. JAMA. 2021;325(10):998–999. doi:10.1001/jama.2021.1505
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  6. Table: Conditions for which COVID-19 vaccination can be considered [Internet]. immunisationhandbook.health.gov.au. [cited 2024 Aug 27]. Available from: https://immunisationhandbook.health.gov.au/resources/tables/table-conditions-for-which-covid-19-vaccination-can-be-considered
  7. Tazarghi A, Bazoq S, Taziki Balajelini MH, et al. Liver injury in COVID-19: an insight into pathobiology and roles of risk factors. Virol J. 2024;21:65. https://doi.org/10.1186/s12985-024-02332-y
  8. Qiu H, Li J, Li J, Li H, Xin Y. COVID-19 and Acute Cardiac Injury: Clinical Manifestations, Biomarkers, Mechanisms, Diagnosis, and Treatment. Curr Cardiol Rep. 2023 Aug;25(8):817-829. doi: 10.1007/s11886-023-01902-w. Epub 2023 Jun 14. PMID: 37314650.
  9. Jeong H, Malik A, Boricha A, et al. Assessment of blood markers to predict risk of stroke in middle-aged to elderly population using machine learning. Sci Rep. 2021;11(1):13422. doi:10.1038/s41598-021-92220-0.
  10. Aklilu AM, Kumar S, Nugent J, et al. COVID-19−Associated Acute Kidney Injury and Longitudinal Kidney Outcomes. JAMA Intern Med. 2024;184(4):414–423. doi:10.1001/jamainternmed.2023.8225
  11. Cidade JP, Coelho LM, Costa V, et al. Septic shock 3.0 criteria application in severe COVID-19 patients: An unattended sepsis population with high mortality risk. World J Crit Care Med. 2022 Jul 9;11(4):246-254. doi: 10.5492/wjccm.v11.i4.246. PMID: 36051940; PMCID: PMC9305684
  12. Gando S, Akiyama T. Disseminated intravascular coagulation is associated with poor prognosis in patients with COVID-19. Sci Rep. 2024;14:12443. https://doi.org/10.1038/s41598-024-63078-9.
  13. Martin AI, Rao G. COVID-19: A Potential Risk Factor for Acute Pulmonary Embolism. Methodist Debakey Cardiovasc J. 2020 Apr-Jun;16(2):155-157. doi: 10.14797/mdcj-16-2-155. PMID: 32670476; PMCID: PMC7350811.
  14. Multisystem Inflammatory Syndrome in Children (MIS-C) – Symptoms and Causes [Internet]. mayoclinic.org. [cited 2024 Aug 27]. Available from: https://www.mayoclinic.org/diseases-conditions/mis-c-in-kids-covid-19/symptoms-causes/syc-20502550#:~:text=But%20in%20children%20with%20MIS,have%20had%20a%20known%20infection.
  15. Vu QM, Fitzpatrick AL, Cope JR, Bertolli J, Sotoodehnia N, West T, et al. Estimates of Incidence and Predictors of Fatiguing Illness after SARS-CoV-2 Infection. Emerg Infect Dis. 2024;30(3):539-547. https://doi.org/10.3201/eid3003.231194
  16. Rhabdomyolysis is a life-threatening complication in patients with COVID-19 [Internet]. ijidonline.com. [cited 2024 Aug 27]. Available from: https://www.ijidonline.com/article/S1201-9712(23)00713-0/fulltext#:~:text=Rhabdomyolysis%20is%20a%20life%2Dthreatening,in%20patients%20with%20COVID%2D19
  17. COVID-19 related stroke in young individuals [Internet]. thelancet.com. [cited 2024 Aug 27]. Available from: https://www.thelancet.com/article/S1474-4422(20)30272-6/fulltext
  18. Association Between Guillain-Barré Syndrome and COVID-19 Infection and Vaccination [Internet]. neurology.org. [cited 2024 Aug 27]. Available from: https://www.neurology.org/doi/10.1212/WNL.0000000000207900
  19. Post-COVID conditions: Information for healthcare providers. Centers for Disease Control and Prevention. https://www.cdc.gov/coronavirus/2019-ncov/hcp/clinical-care/post-covid-conditions.html. Accessed 19 October 2022
  20. Post-COVID-19 conditions. Centers for Disease Control and Prevention.
  21. COVID-19 (coronavirus): Long-term effects, Mayo Clinic, https://www.mayoclinic.org/diseases-conditions/coronavirus/in-depth/coronavirus-long-term-effects/art-20490351. Accessed 19 October 2022
  22. WHO Post COVID 19 condition (Long Covid) Fact sheet Accessed 26 April 2023
  23. Australian Government Australian Institute of Health and Welfare Long COVID in Australia- a review of the literature Last updated 16 December 2022
  24. Brosh-Nissimov T et al. Clin Microbiol Infect. 2021;27:1652–1657
  25. High-risk groups for severe illness from COVID-19 [Internet]. health.gov.au. [cited 2024 Aug 27]. Available from: https://www.health.gov.au/topics/covid-19/protect-yourself-and-others/high-risk-groups
  26. Tenforde MW et al. Clin Infect Dis. 2021;ciab687
  27. Australian Government Department of Health Protect yourself and others from COVID 19 Last updated 14 October 2022
  28. ATAGI statement on the administration of COVID-19 vaccines in 2024 [Internet]. health.gov.au. [cited 2024 Aug 27]. Available from: https://www.health.gov.au/sites/default/files/2024-03/atagi-statement-on-the-administration-of-covid-19-vaccines-in-2024.pdf
  29. Oral treatments for COVID-19 [Internet]. health.gov.au. [cited 2024 Aug 27]. Available from: https://www.health.gov.au/topics/covid-19/oral-treatments
  30. Paxlovid® (nirmatrelvir and ritonavir) Product Information [Internet]. tga.gov.au. [cited 2024 Aug 27]. Available from: https://www.tga.gov.au/sites/default/files/paxlovid-pi.pdf
  31. Lagevrio® (molnupiravir) Product Information [Internet]. tga.gov.au. [cited 2024 Aug 27]. Available from: https://www.tga.gov.au/sites/default/files/lagevrio-pi.pdf
  32. BMJ Best Practice. COVID-19: assessment of severity [Internet]. London (GB): BMJ Publishing Group; 2024 [cited 2024 Nov 22]. Available from: https://bestpractice.bmj.com/topics/en-gb/3000201/criteria?