fortunately dangerous side effects or reactions to vaccines are few and rare. reactions that are life-threatening or result in lasting disability are very rare. however it is important to note that vaccines like any other medical product potentially come with some risk no matter how small. one type of rare serious reaction is anaphylaxis a severe allergic reaction. it occurs on the order of approximately one case per million doses of vaccinations administered. in case of severe allergic reactions including anaphylaxis urgent emergency treatment is required.
are there dangerous side effects or reactions to childhood vaccines?