One of the most important things parents can do for their children is to make sure they are immunized against infectious diseases such as measles, mumps, rubella, polio, tetanus, diphtheria, pertussis, meningococcal meningitis, rotavirus, Haemophilus influenza type b, pneumococcal pneumonia and meningitis, hepatitis A and B, influenza and varicella.

These diseases are now rare in the United States – so rare, in fact, that many people don’t understand how serious and even deadly they can be.

In countries without effective immunization programs, these diseases strike both children and adults, and spread rapidly through communities. Because international travel is so common now, these diseases are sometimes carried to the United States by travelers. A single case of a disease can turn into an epidemic without widespread immunization programs.

There have been no research studies that prove vaccines cause autism or other developmental disorders. In fact, there are not concerns about the vaccines themselves, but rather thimerosal – a mercury-based preservative used in some vaccines prior to 2001.