The most common side effect of the chickenpox vaccine is soreness and redness around the site of the injection. This happens in around one in five children and one in four teenagers and adults. A mild rash may develop in one in 10 children and one in 20 adults.
Serious side effects, such as anaphylaxis (a serious allergic reaction), are rare. They occur in around one in a million vaccination cases.
Although the varicella vaccine is not part of the routine NHS childhood immunisation schedule in the UK, it is in other countries, such as the US and Germany.
Millions of doses of the vaccine have been given and there is no evidence of any increased risk of developing a long-term health condition as a result of the vaccination.
This Public Health England leaflet (PDF, 64.4kb) tells you the common vaccination reactions that may happen in babies and young children up to five years of age.
Read more about vaccine side effects.
Monitoring safety of vaccines
In the UK, the safety of vaccines is monitored through the Yellow Card Scheme by the Medicines and Healthcare products Regulatory Agency (MHRA) and the Commission on Human Medicines.
Most reactions reported through the Yellow Card Scheme have been minor, such as redness and swelling at the injection site, rashes, fever and vomiting.
Find out how to report a vaccine side effect.