Chickenpox (Varicella)

Symptoms of chickenpox generally start to appear two to three weeks after exposure to the virus. They include irritability with a mild fever and rash, usually presenting on the chest first. Spots can look like pimples or blisters. These spots turn into blisters, which burst, forming scabs in about five days. Complications can include pneumonia, scarring and shingles later in life. Chickenpox can be a very disruptive illness for young adults as the severity of the disease increases with age.

The most effective preventative measure for chickenpox is vaccination. It is estimated that the vaccine has an efficacy of 90% against infection and 95% against severe infection. High levels of vaccination in the community create herd immunity, which helps protect people who cannot be vaccinated.

Vaccination against chickenpox is part of the standard childhood immunisation schedule in Australia, and one varicella vaccine dose is routinely given at 18 months of age. In 2022, ATAGI recommended that all children under 14 receive a second dose to prevent break-through infections. At the time of writing, this second dose is not funded.

Individuals over 14 and adults who are not immune to chickenpox can receive a vaccination course of two doses given at least four weeks apart.

Breakthrough chickenpox may occur in those who have been vaccinated, but it is generally a much milder disease.

Calamine lotion can relieve the itchiness of the rash once it appears. In some instances, oral antiviral therapy may be considered and should be given within the first 24 hours after the varicella rash starts.

If you have been exposed to chickenpox and are not immune, you may receive vaccination within five days of exposure (preferably within three) or, if you are at risk of serious illness, an injection of varicella zoster immune globulin (VZIG), ideally within four days of exposure.