All medicines (including vaccines) are tested for safety and effectiveness before they are allowed to be used. Once they are in use, their safety continues to be monitored by the Medicines and Healthcare products Regulatory Agency (MHRA). The MHRA is the UK regulatory authority for medicines and vaccines.
Although all medicines may cause some side effects, vaccines are among the safest of all medicines. Worldwide research shows that the safest way to protect your child's health is by getting them vaccinated.
Most side effects from vaccinations are mild and do not last long, and not everyone gets them. Different vaccinations can have different side effects.
You can find information about side effects for each vaccine at:
A to Z list of vaccinations - Public Health Wales (nhs.wales)