Vaccines are among the safest medical products available, and scientists are working to make sure they are made even safer. Every vaccine undergoes extensive testing before being licensed, and vaccine safety continues to be monitored as long as a vaccine is in use.
Most side effects from vaccination are minor, such as soreness where the injection was given or a low-grade fever. These side effects do not last long and are treatable.
Serious reactions are very rare. The tiny risk of a serious reaction from a vaccination has to be weighed against the very real risk of getting a dangerous vaccine-preventable disease or suffering complications from it.