Varicella (chickenpox)

Page last updated: 20 April 2015

Varicella (chickenpox) is a highly contagious infection caused by the varicella-zoster virus, which is a member of the herpes group of viruses. It is usually a mild disease that lasts a short time in healthy children. However, it can be severe in adults and may cause serious or even fatal complications in people of any age.

Vaccination of children against chickenpox not only prevents serious disease in childhood, but also ensures immunity in adolescence and adulthood, when complications from the disease can have severe outcomes. Vaccination has been highly effective in reducing varicella hospitalisations among young children in Australia.


Chickenpox is highly contagious, and is spread through the air, by coughing, sneezing or direct contact with people who are infected. About 90% of unvaccinated people who have not previously had chickenpox will become infected when they come into contact with the virus.


Symptoms of chickenpox take between 10 and 21 days (14 to 16 days on average) to show after infection. The main symptom is an itchy red rash that turns into open lesions or small wounds, which then crust over. Chickenpox can also cause flu-like symptoms, such as fever, headache and sore throat.

Complications of the disease can include: infection of the lesions, pneumonia (lung infection), difficulty walking and balancing, meningitis (infection of the membrane surrounding the brain), and encephalitis (brain infection).

Infection during pregnancy can result in congenital abnormalities in the baby. The varicella virus can also reactivate many years after the initial infection and cause shingles (herpes zoster).


Chickenpox is a vaccine preventable disease, and vaccination is recommended as part of routine childhood immunisation. The vaccine should not be given to children with severe immune deficiency diseases, including HIV/AIDS, or to any child taking high doses of immune suppressing medicine.

The varicella vaccine is free under the National Immunisation Program Schedule. To receive immunisation, visit your local doctor or immunisation provider. It is important to note that although the vaccine is provided at no cost, a consultation fee may apply.

Immunisation against chickenpox is achieved in one dose of the MMRV (measles-mumps-rubella-varicella) combination vaccine at 18 months of age.

A catch-up program is available for children aged 10-13 years who have not received the varicella vaccine.

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