{"id":17490,"date":"2023-02-07T13:07:49","date_gmt":"2023-02-07T02:07:49","guid":{"rendered":"https:\/\/mvec.mcri.edu.au\/?post_type=references&p=17490"},"modified":"2026-06-23T10:48:58","modified_gmt":"2026-06-23T00:48:58","slug":"%e6%96%b0%e5%86%a0%e8%82%ba%e7%82%8e","status":"publish","type":"references","link":"https:\/\/mvec.mcri.edu.au\/zh\/references\/covid-19\/","title":{"rendered":"\u65b0\u51a0\u80ba\u708e"},"content":{"rendered":"
<\/p>\n

What is it?<\/h2>\n

COVID-19 disease is caused by infection with the SARS-CoV-2 virus of which there are many different strains and subvariants.\u00a0\u00a0<\/span><\/p>\n

Since its emergence in 2019, COVID-19 disease has had vast impacts on society including a global pandemic. In addition to the public health implications, the economic, social and mental health effects have been and continue to be significant.\u00a0 <\/span>\u00a0<\/span><\/p>\n

What to look for?<\/h2>\n

Infections can be asymptomatic or can result in a spectrum of symptoms, from mild respiratory symptoms to more serious disease affecting multiple organs and systems. Severe disease can lead to hospitalisation, mechanical ventilation, and can be fatal.\u00a0\u00a0\u00a0<\/span>\u00a0<\/span><\/p>\n

Common symptoms of acute infection include rhinorrhoea (runny nose), sneezing, headache, sore throat and fatigue. The symptoms of fever, loss of smell or taste and persisting cough were features comonly seen in infections with earlier variants (Alpha, Beta, Gamma, Delta).<\/span>\u00a0<\/span><\/p>\n

Long COVID is a chronic condition that can occur following acute infection. It is the persistence of symptoms for greater than 3 months after an initial infection that cannot be attributed to other causes. Long COVID can have a huge impact on an individual\u2019s quality of life, mental health and ability to participate in work or schooling. Long COVID is more common in people who have experienced severe COVID-19 disease, those who had underlying medical conditions prior to infection (e.g. hypertension, chronic lung disease, diabetes, obesity) and those who are unvaccinated.\u00a0<\/span>\u00a0<\/span><\/p>\n

Paediatric Multisystem Inflammatory Syndrome Temporally associated with SARS-CoV-2<\/a> (PIMS-TS), or Multisystem Inflammatory Syndrome in Children associated with COVID-19 (MIS-C), is a newly described condition that has been reported in children in the first 2-6 weeks after COVID-19 infection. It is an inflammatory condition, similar to Kawasaki disease<\/a>, and is characterised by rash, fever, shock and abdominal pain. Children experiencing PIMS-TS almost always require hospitalisation for treatment.<\/p>\n

How is it transmitted?<\/h2>\n

COVID-19 is transmitted through the inhalation of virus particles made airborne when an infected person coughs, sneezes, breathes, speaks or sings. Droplets containing virus particles can contaminate surfaces and can be spread when a person touches these surfaces and then touches their nose, mouth or eyes. Poorly ventilated settings can also contribute to the spread of COVID-19 because aerosol particles can remain suspended in the air for several hours longer than in well-ventilated settings.<\/span>\u00a0<\/span><\/p>\n

The incubation period for the disease is 1 to 14 days, with most individuals displaying symptoms 3 days after being exposed. Individuals are most infectious in the 2 days before their symptoms begin and the early stages of their illness. People with asymptomatic disease can still infect others.\u00a0\u00a0<\/span>\u00a0<\/span><\/p>\n

Epidemiology<\/h2>\n

Serosurveys<\/a> <\/span>indicat<\/span>e that by December 2022 more than two<\/span> thirds of adult Australians had been infected with SARS-<\/span>CoV<\/span>-2.<\/span><\/span><\/span><\/span><\/p>\n

Individuals with immunocompromise, advancing age (particularly > 70 years), obesity, respiratory conditions, heart disease, diabetes, renal disease, liver disease, neurological conditions and disability are more likely to experience severe symptoms if infected with SARS-CoV-2. Pregnancy in unvaccinated people is also recognised as a risk factor for developing severe disease; however, this risk has declined substantially with the emergence of newer variants (Omicron).<\/span>\u00a0<\/span><\/p>\n

Certain occupations, such as working in healthcare, increase likelihood of exposure to SARS-CoV-2 and therefore infection.\u00a0\u00a0<\/span>\u00a0<\/span><\/p>\n

Prevention<\/h2>\n

Strategies to reduce risk of transmission of COVID-19 disease include standard precautions such as hand hygiene, wearing masks when remaining socially distant is not possible and ensuring indoor spaces have good ventilation.\u00a0\u00a0<\/span>\u00a0<\/span><\/p>\n

While natural infection does provide some immunity, it is not lifelong, and the emergence of newer strains contributes to repeat infections.<\/span>\u00a0<\/span><\/p>\n

Vaccination aims to reduce the severity of COVID-19 symptoms and the need for hospitalisation. There is one vaccine brand available for use within Australia:<\/span><\/p>\n

    \n
  • Comirnaty (Pfizer) vaccine containing <\/span>nucleoside-modified mRNA encoding the spike glycoprotein of SARS-CoV-2.<\/span><\/li>\n<\/ul>\n

    As newer variants of <\/span>the <\/span>SARS-CoV-2 virus <\/span>emerge<\/span>, <\/span>vaccines <\/span>are<\/span> updated <\/span>to <\/span>target the strains that are <\/span>circulating<\/span>; <\/span>where possible<\/span>,<\/span> these should be used preferentially<\/span>.<\/span><\/span>\u00a0<\/span><\/p>\n

    Table 1: Vaccine brands and type available for use by age group<\/strong><\/p>\n<\/div>\n\t

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