Chickenpox (varicella) vaccine

Vaccine

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This vaccine gives protection against chickenpox infection. For those who are vaccinated but still get chickenpox, the symptoms will generally be milder.

In the UK the chickenpox vaccine is not currently part of the routine childhood schedule.  However, the Joint Committee on Vaccination and Immunisation (JCVI), who make recommendations to the UK Government on vaccine policy, recently recommended that this vaccine should now be included. Therefore, the chickenpox vaccine could become a part of the UK routine childhood schedule in the future. See the ‘more information about this vaccine’ below.

The vaccine is currently recommended for those in close contact with people who are particularly at risk of complications from chickenpox. Further information is available in the 'Who should get this vaccine?' section below.

Two doses of the vaccine are given as two separate injections at least four weeks apart. These give about 98% protection in children and about 75% protection in teenagers and adults.

The vaccine contains a live strain of the varicella-zoster (chickenpox) virus which has been weakened (attenuated). This stimulates the immune system but does not cause disease in healthy people.

 

In the UK, the chickenpox vaccine is recommended for adults and children over the age of one year in close contact with people who are particularly at risk of complications from chickenpox. This includes:

  • Healthcare workers who are not immune to chickenpox
  • Healthy family members and contacts of people without a fully-working immune system (for example, those with HIV, those without a spleen, people who have had an organ transplant, and those receiving chemotherapy treatment). As the chickenpox vaccine is a live vaccine, people without a fully-working immune system cannot receive the vaccine themselves.
  • Laboratory workers who are not immune to chickenpox and who may come into contact with the virus as part of their job.

The chickenpox vaccine should not be given to people who are clinically immunosuppressed, either due to drug treatment or underlying illness.

The chickenpox vaccine is not recommended for pregnant women as a matter of caution.

 

All vaccines go through rigorous testing and regulatory processes that can take up to 15 years to ensure they are safe and effective. Like all medicines, vaccines can cause side effects, but not everyone gets them.

The frequency and type of side effects are slightly different for the two chickenpox vaccines used in the UK. For full information on side effects, ask for the patient information leaflet for the vaccine you are offered. As a general guide, the following side effects may be experienced:

Very common - affecting more than 1 in 10 people at each dose:

  • reactions at the site of the injection, including redness, pain and swelling.
  • raised temperature (fever)

Common - affecting up to 1 in 10 people at each dose

  • chickenpox-like rash (in up to 10% of adults and 5% of children)
  • mild cold-like symptoms
  • irritability
  • itching at the injection site

Uncommon - affecting up to 1 in 100 people at each dose:

  • swollen glands, headache, sore throat, cough, or runny nose
  • feeling sick or being sick
  • diarrhoea
  • a rash with blisters
  • joint or muscle pain
  • very high temperature
  • drowsiness, tiredness, or feeling generally unwell

For rarer side effects - affecting fewer than 1 in 1000 people - please read the patient Information leaflets for Varivax and Varilrix.

As with any vaccine, medicine or food, there is a very small chance of a severe allergic reaction (anaphylaxis). Anaphylaxis is different from less severe allergic reactions because it causes life-threatening breathing and/or circulation problems. It is always extremely serious but can be treated with adrenaline. Health care workers who give vaccines know how to do this.

In the UK between 1997 and 2003 there was a total of 130 reports of anaphylaxis following ALL immunisations. Around 117 million doses of vaccines were given in the UK during this period. This means that the overall rate of anaphylaxis is around 1 in 900,000.

If you are concerned about any reactions that occur after vaccination, consult your doctor. In the UK you can report suspected vaccine side effects to the Medicines and Healthcare products Regulatory Agency (MHRA) through the Yellow Card Scheme. You can also contact the MHRA to ask for data on Yellow Card reports for individual vaccines. See more information on the Yellow Card scheme and monitoring of vaccine safety.

 

Two brands of chickenpox vaccine are used in the UK: Varilrix (see the patient information leaflet) and Varivax (see the patient information leaflet).

Apart from the active ingredients (the antigens), the vaccines may contain very small amounts of these added ingredients:

  • sorbitol, mannitol, lactose or urea - safe organic compounds used as stabilisers

The vaccines may also contain traces of these products used during the manufacturing process:

  • neomycin - an antibiotic used to stop bacteria growing and contaminating the vaccine
  • harmless salts based on sodium and potassium - used as acidity regulators

The virus strain used in both vaccines is grown in the laboratory using human cell strains. It is unlikely that human material remains in the final vaccine.

Highly purified porcine gelatine is used as a stabiliser in the Varivax vaccine. There is no gelatine in Varilrix. 

Other brands of chickenpox vaccine used in other countries may contain different ingredients. If you are not in the UK, ask for the patient information leaflet for the vaccine you are offered.

 

More information about who should not have the vaccine

People who are clinically immunosuppressed should not have this vaccine because the vaccine strain could replicate too much and cause a serious infection. This includes babies whose mothers have had immunosuppressive treatment while they were pregnant or breastfeeding. For more information see the MHRA's Drug Safety Update (April 2016).

The chickenpox vaccine is not recommended for pregnant women as a matter of caution. However, studies have not shown any link between the weakened virus in the vaccine and any specific problems in babies born to women who received a chickenpox vaccine while they were pregnant. These have not shown any link between the weakened virus in the vaccine and any specific problems in babies born to these women. See this Public Health England statement for more information.

Studies have shown that the vaccine virus does not get passed to the baby through breast milk, so it is safe for breast-feeding women to be vaccinated (see the Green Book chapter on Varicella, page 438).

Why the chickenpox vaccine is not offered routinely in the UK 

The Joint Committee on Vaccination and Immunisation (JCVI), who makes recommendations to the UK Government on vaccine policy, released a statement on the 14th of November 2023 recommending that the chickenpox vaccine should be introduced as part of the routine childhood schedule. This would be a two-dose schedule at 12 and 18 months using the combined MMRV (measles, mumps, rubella, and varicella vaccine). 

Data from other countries that include the chickenpox vaccine as part of their routine schedules show that cases of chickenpox in children will reduce rapidly. A catch-up programme is also recommended following this policy change to ensure there isn’t an immunity gap.

Previous recommendations were made based on the data available at the time, and it was thought that cases of shingles in older people would increase if the chickenpox vaccine was included in the immunisation schedule.

Shingles is very expensive for the NHS to treat. It was believed that many adults in the UK get their immunity to chickenpox boosted by coming into contact with children who have the disease. Several studies have shown that this may make adults less likely to develop shingles as they get older.

However, the JCVI has reviewed data from other countries where the vaccine has been in routine use over the past decade or two. The data do not show that the chickenpox vaccination programmes increase the cases of shingles.

See the JCVI statement here.

Information about other treatments

A treatment called human varicella zoster immunoglobulin (VZIG) is given to people in risk groups who have been exposed to chickenpox. Immunoglobulins are special concentrated antibody preparations which provide immediate short-term protection against disease. VZIG can help to reduce the severity of chickenpox symptoms for some people in risk groups.

Chickenpox vaccine outside of the UK

The chickenpox vaccine currently available in the UK is a single vaccine. However, several countries use a vaccine that combines the measles, mumps and rubella (MMR) vaccine with a chickenpox (varicella) vaccine, called the MMRV vaccine. The MMRV vaccine is the recommended vaccine by the JCVI.

For children aged two and younger, studies have shown that more of them develop fever after the MMRV vaccine, compared with giving the MMR vaccine and the chickenpox vaccine separately on the same day. In particular, there is an increased risk of febrile convulsions (fits). These occur 7-10 days after MMRV vaccination. Febrile seizures are unlikely to cause long-term effects and the overall risk is very low.

 

Page last updated Tuesday, November 21, 2023