Vaccines work by fooling our immune system into thinking we have been infected by the real bacteria or virus. The vaccine looks like the disease but does not cause illness. When we are exposed to the real illness our immune system is ready to fight it off before it has a chance to make us sick.
Our modern day vaccines can prevent a variety of serious infections that include; whooping cough (pertussis), lockjaw (tetanus), diphtheria (a severe throat infection), meningitis (a brain infection), chicken pox, measles, mumps, rubella, the crippling disease polio, liver infections (hepatitis A and B), the stomach virus rotavirus and cervical cancer in women (HPV vaccine).
Vaccines have proved remarkably safe, as well as, successful at preventing disease. But like most preventative medicines it is hard for most people to appreciate the effectiveness when nothing happens. Most people have never seen these diseases that we try to prevent. The only way to keep the infections away from your child is to vaccinate.