As with any medication, there is always the risk of side effects and vaccines are no different. However, the risks of side effects are far smaller than the risk of the diseases they prevent. The main side effects children appear to have after a vaccine are fevers, injection site pain, occasional rashes and feeling ‘under-the-weather’, or a bit grumpy. There may be specific side effects associated with particular vaccines, and these will be discussed with individual patients/parents.