Usual symptoms

• Most children who get varicella get a fever, and between 200 and 500 itchy, fluid-filled blisters on their skin. These blisters can get infected.
• When pregnant women catch varicella their babies usually suffer serious and permanent injuries.
• As many as 33 per cent of babies born to mothers who catch varicella around the time they give birth get a severe form of varicella infection.
• About 1.4 per cent of babies whose mothers had varicella during the second trimester of their pregnancies are born with scarred skin or congenital malformations (arms, legs, eyes or brains that haven’t formed normally).
• As many as 1.6 per cent of babies whose mothers had varicella during the third trimester of their pregnancies can get shingles. Shingles (herpes zoster) causes a blistery rash, headaches, eyes that hurt in the light (photophobia), severe tiredness or lack of energy, itching, tingling and severe nerve pain.

Very rare symptoms

• About 0.025 per cent of people with varicella develop a condition called cerebellar ataxia which affects their brains and affects their coordination, making  them unable to walk normally.
• About 0.001 per cent develop a brain infection called encephalitis.
• Varicella can also cause pneumonia (lung infection).
• Varicella can cause children to bruise or bleed very easily (thrombocytopenia). It usually lasts for between one and six months and then gets better.
• Occasionally, varicella can affect people’s joints and internal organs.

In Australia, children receive the MMRV vaccine, which strengthens immunity to varicella, as well as measles, mumps and rubella.

It is recommended that children get a vaccine that protects against varicella (chickenpox) at 18 months.

It is important that children get all their vaccinations on time to ensure they have the  best possible protection against infectious diseases.

No, there is no risk that your child will catch varicella because the varicella-containing vaccine, MMRV, only contains a weakened form of the varicella virus. This weakened virus trains your child’s immune system to recognise and fight the disease, but does not cause the disease. Occasionally, children receiving the vaccine may develop a high fever and a localised rash similar to varicella disease, but they fully recover. 

Children with cancer or serious immune system diseases should not have live vaccines, including MMRV, as they can become very unwell. Your immunisation provider will screen for these conditions before giving your child their vaccine.  

• Between 7 and 30 per cent of children who get a vaccine that protects against varicella (chickenpox) experience local swelling, redness or pain at the injection site. These symptoms usually resolve within one or two days.
• About 15 per cent get a high fever and tiredness or lack of energy (malaise) between 5 and 12 days after they get the vaccine. 
• About 5 per cent get a few varicella-like spots that appear between five and 26 days after vaccination and last for about a week.
• Up to 1.6 per cent get swollen glands, stiff neck or joint pains that can start between 10 and 14 days after vaccination.

• About 0.03 per cent of children who get a first dose of a vaccine that protects against varicella experience febrile convulsions (fits). These happen when babies’ or children’s temperature (fever) goes up suddenly. Febrile convulsions don’t have long-term effects on a child’s health and development.
• Between 0.003 and 0.005 per cent develop a blood disorder called thrombocytopenia (a low platelet count in the blood) after their first dose of a vaccine that protects against measles, mumps and rubella. Thrombocytopenia causes children to bruise or bleed very easily. It usually lasts for between one and six months and then gets better.
• About 0.0001 per cent can have an allergic reaction after vaccination that affects their whole body, called anaphylaxis. This reaction usually happens within 15 minutes of getting the vaccination and can be treated by giving an injection of adrenaline. People who have this reaction usually recover quickly and don’t experience any long-term effects.
• These side effects are less common after the MMRV vaccine (given at 18 months) because it is the second dose of a vaccine that contains MMR.

Hospitalisation rates due to varicella started to drop significantly with the introduction of the funded varicella vaccine in 2005.²