Alternative tile: Chickenpox

What is it?

Chickenpox is a very contagious disease caused by the varicella-zoster virus (VZV).

What to look for?

The classic symptom of chickenpox is a rash that turns into itchy, fluid-filled blisters that eventually turn into scabs. The rash may first show up on the face, chest, and back then spread to the rest of the body, including inside the mouth, eyelids, or genital area. It usually takes about one week for all the blisters to become scabs. Other typical symptoms that may begin to appear 1-2 days before rash include high fever, tiredness, loss of appetite and headache.

How is it transmitted?

Chickenpox transmission is mainly person to person by air transport or coughing infected droplets, but also by direct contact with vesicle fluid of chickenpox cases. It is also possible to get infected through contact with the vesicle fluid of patients with Shingles (herpes zoster – see resources). Indirect contact occurs through articles freshly soiled by discharges from vesicles of infected persons. Scabs are not infective.

Am I already protected?

Chickenpox is highly infectious with over 80% of non-immune household contacts of a case of chickenpox likely to become infected. Second attacks of chickenpox are rare but do occur. The virus can recur years later as shingles. This is because the virus remains in nerve cells and can be reactivated.

Vaccination offers the best protection for those that have not been exposed to chickenpox. The Australian varicella immunisation program has seen a dramatic reduction in the number of children admitted to hospital with varicella and it’s associated complication (e.g. secondary skin infection)

Vaccination to prevent infection?

In Australia, the varicella vaccine is recommended for non-immune, healthy individuals aged 12-months or older.  One dose of vaccine is routinely administered at 18-months of age on our National Immunisation Program. It is now administered as a combined measles-mumps rubella-varicella vaccine. There is also a catch-up dose currently administered to adolescents in Victoria in Year 7 at secondary school. Varicella should be given on the same day or 1-month after other live vaccines (e.g. MMR)

Adverse events following vaccination with varicella-containing vaccines are generally mild and well tolerated.  Injection site reactions (pain, redness, and swelling) can be seen and a varicella vaccine associated rash (small number of vesicles 3-30 days following immunisation) can occur.

Special risk groups

It is not routinely recommended to administer chickenpox vaccine if a patient is on immune suppression (e.g. cancer chemotherapy; immune suppression medication)- discuss this with your treating specialist.

The vaccine can be administered to children > 9-months of age in the setting of a chickenpox contact (e.g at childcare). This should be within 72-hours of exposure if possible. If a dose is given early, the routine varicella (chickenpox vaccine) should still be administered at 18-months.

Non-immune individuals who should be specifically targeted for vaccination include household contacts of immunosuppressed individuals, health care workers, those working with young children, and parents of young children.


The Royal Children’s Hospital, Melbourne has an excellent Chickepox Clinical Practice Guideline

The Better Health Channel has an excellent resource on Shingles (Herpes Zoster)

Reviewed by: Nigel Crawford (Paediatrician, The Royal Children’s Hospital, Melbourne)
Date: July 2014
Materials in this section are updated as new information and vaccines become available. The Melbourne Vaccine Education Centre (MVEC) staff regularly reviews materials for accuracy.
You should not consider the information in this site to be specific, professional medical advice for your personal health or for your family’s personal health. For medical concerns, including decisions about vaccinations, medications and other treatments, you should always consult a healthcare professional.

Melbourne University

Welcome to MVEC

The Melbourne Vaccine Education Centre (MVEC) is a new web-based initiative, providing up-to-date immunisation information for healthcare professionals, parents and the public.

It is a collaboration between The Royal Children’s Hospital (RCH) and its Melbourne Children’s campus partners (Murdoch Children's Research Institute and The University of Melbourne) and Monash Health.

MVEC aims to address common queries around vaccines and to promote the benefits of immunisation for both children and adults.