Can a vaccine give me or my child the disease it’s supposed to prevent?

It isn’t possible for inactivated (killed) vaccines to cause disease. This is because a germ has to be alive to cause disease.

 

Some vaccines contain weakened live versions of the whole germ, such as Measles, Mumps, Rubella (MMR) vaccine, and chickenpox (varicella) vaccine. These weakened germs in live vaccines will not cause the disease in a person with a healthy immune system. However, live vaccines are not given to people with very weak immune systems as they may develop the disease the vaccine is meant to protect against. Your health care provider will make sure that you or your child can safely receive a live vaccine before giving it.