Chickenpox is caused by the varicella-zoster virus (VZV) and it is a highly infectious disease that usually causes an itchy red rash with blisters. It is one of the most common childhood diseases, although it can affect adults as well. Most people recover fully from chickenpox, but it can cause complications. A child with chickenpox can miss up to two weeks of school.
Immunisation against chickenpox is included in the combination measles, mumps, rubella and varicella (MMRV) vaccine for children at 18 months. Until the end of 2017, the varicella vaccine (VV) is also r offered to all 12-13 year old adolescents in year 7 of secondary school through a school-based catch-up program.
Complications of chickenpox
Most people recover fully from chickenpox without ongoing problems, but it can cause complications in some adults and children and in people who have weakened immune systems. The complications may include:
- scarring – chickenpox can leave pockmark scars on the skin
- cellulitis – a type of bacterial infection of the skin
- pneumonia – infection and inflammation of the lung can occur in adults and can be fatal
- encephalitis – inflammation of the brain, usually mild, but sometimes severe
- bleeding disorders – rare but can be fatal
- death – in rare cases
- shingles can occur in people who have previously had chickenpox.
Reasons for chickenpox immunisation
Immunisation can prevent serious medical complications. For children who have not had chickenpox, the vaccine can help protect them against serious complications associated with chickenpox and protect them from developing shingles later in life. Immunised children who get chickenpox generally have a much milder form of the disease. They have fewer skin lesions, a lower fever and recover more quickly.
Research shows that two doses of chickenpox vaccine in children provides increased protection and reduces the risk of chickenpox occurring at a later time. The government funds one free dose of chickenpox vaccine and a parent can purchase, on prescription, a second dose four to six weeks later if they wish.
Immunisation against chickenpox is provided free of charge to children under the National Immunisation Program Schedule. Either of two vaccines are used depending on age. The first is a combined vaccine containing protection against measles, mumps, rubella and varicella (MMRV) given at 18 months of age. The second is the varicella vaccine (VV), which immunises only against chickenpox given in year 7 of secondary school or at 12-13 years of age.
In Victoria, immunisation against chickenpox is free for:
- Children at 18 months – immunisation against chickenpox is given as the combination MMRV vaccine. Children who have had chickenpox should still receive the combination vaccine. Adolescents in year 7 of secondary school or aged 12-13 years are offered the VV at school. It is recommended for adolescents who have not already had chickenpox or who have had one previous dose of VV. It can safely be given to adolescents who are unsure if they have had previous chickenpox infection.
- Children up to and including nine years of age – may require a catch-up immunisation.
Other adults with no reliable history of chickenpox disease can have a blood test to check their immunity and if they are not immune, they can purchase it with a prescription. MMRV is not recommended for people 14 years and over. People in this age range will be immunised with VV and should be given two doses of VV, one to two months apart. Your immunisation provider can give you more information.
Both the combination MMRV vaccine and the VV contain a weakened form of VZ that works by causing the body to produce its own antibodies to protect against the virus.
People who should be immunised against chickenpox
People who benefit most from immunisation include:
- adults not immune to chickenpox (those who have not been immunised and have not had chickenpox), especially parents with young children and people in ‘at-risk’ occupations such as teachers, childcare workers and healthcare workers
- adults and young children who are not immune (those who have not been immunised and have not had chickenpox), and who live with people with weakened immune systems and no history of chickenpox.
Pregnancy and chickenpox immunisation
If you are thinking of becoming pregnant or you are early in your pregnancy, your healthcare professional can check your immunity with a blood test. If you are not immune and not pregnant, you may decide to receive the VV before you become pregnant. The MMRV vaccine is not recommended for people 14 years and over.
If you are not immune during your pregnancy, you should avoid contact with people who have known cases of chickenpox. Contact your doctor, midwife or hospital as soon as possible if you are exposed to anyone with chickenpox.
Before receiving the vaccine, tell your doctor or nurse if you (or your child):
- are unwell (have a temperature over 38.5 ˚C)
- have allergies to any other medicines or substances
- have had a serious reaction to any vaccine
- have had a serious reaction to any component of the vaccine
- have had a severe allergy to anything
- have a disease or you are having treatment that causes low immunity
- have received another vaccine within the last month or if you will have another vaccine within one month of the chickenpox immunisation
- have received a blood or plasma transfusion or immunoglobulins within the last three to nine months or will need to receive them within three weeks of the chickenpox immunisation
- are taking any prescription or over-the-counter medicines
- are due to have a skin test for tuberculosis within four to six weeks of receiving the chickenpox vaccine
- are pregnant or intend to become pregnant.
Side effects of chickenpox vaccine
The chickenpox vaccine is effective and safe, but all medications can have unwanted side effects. Side effects from chickenpox vaccine can occur five to 26 days after immunisation and include a mild chickenpox-like rash, usually at the injection site, but occasionally elsewhere on the body.
Other mild side effects occurring in the first few days after immunisation include:
- localised pain, redness and swelling at the injection site
- occasionally, an injection-site lump that may last many weeks (treatment is not needed)
- temperature (fever, can be more than 39 ˚C).
Managing fever after immunisation
Common side effects following immunisation are usually mild and temporary (occurring in the first few days after vaccination).
Side effects can be reduced by:
- drinking extra fluids and not overdressing if the person has a fever
- although routine use of paracetamol after immunisation is not recommended, if fever is present, paracetamol can be given – check the label for the correct dose or speak with your pharmacist, (especially when giving paracetamol to children).
Concerns about side effects
If the side effect following immunisation is unexpected, persistent or severe, or if you are worried about yourself or your child’s condition after immunisation, see your doctor or immunisation nurse as soon as possible or go directly to a hospital.
Immunisation side effects may be reported to the Victorian vaccine safety service, the central reporting service in Victoria on (03) 9345 4143. You can discuss with your immunisation provider how to report adverse events in other states or territories. It is also important to seek medical advice if you (or your child) are unwell, as this may be due to other illness, rather than because of the immunisation.
Rare side effects
There is a very small risk of a serious allergic reaction (anaphylaxis) to any vaccine. This is why you are advised to stay at the clinic or medical surgery for at least 15 minutes following immunisation in case further treatment is required. Apart from anaphylaxis, other extremely rare side effects include thrombocytopenia (bleeding caused by insufficient blood platelets).
Immunisation and HALO
The immunisations you may need are decided by your health, age, lifestyle and occupation. Together, these factors are referred to as HALO.
Talk to your doctor or immunisation provider if you think you or someone in your care has health, age, lifestyle or occupation factors that could mean immunisation is necessary. You can check your immunisation HALO using the Immunisation for Life infographic (pdf)
Where to get help
- Your doctor
- In an emergency, always call triple zero (000)
- Emergency department of your nearest hospital
- Your local government immunisation service
- Maternal and child health nurse
- Maternal and Child Health Line (24 hours) Tel. 132 229
- NURSE-ON-CALL Tel. 1300 60 60 24 – for expert health information and advice (24 hours, 7 days)
- Immunisation Section, Department of Health, Victorian Government Tel. 1300 882 008
- National Immunisation Information Line Tel. 1800 671 811
- Your local pharmacist
- Victorian vaccine safety service Tel. (03) 9345 4143 – the line is attended between 10 am and 3.30 pm and you can leave a message at all other times
Things to remember
- Chickenpox is a highly infectious disease that sometimes causes complications.
- The chickenpox vaccine is of greatest benefit to children over 12 months and people who live with someone with lowered immunity.
- Serious side effects or allergic reactions to the vaccine are rare and should be attended to immediately by your doctor or at the nearest hospital.
This page has been produced in consultation with and approved by:
Department of Health and Human Services - RHP&R - Health Protection - Communicable Disease Prevention and Control Unit
Page content currently being reviewed.
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