CHAPTER 1

• Jurisdiction: United States

CHAPTER 1 WHAT IS THE ROLE OF A VACCINE IN HELPING TO AVOID ILLNESSES?

Immunity is defined as protection from an infectious disease. If you are immune to a disease, you can be exposed to it without becoming infected.

Vaccination is the act of introducing a vaccine into the body to stimulate the recipient's immune system to produce immunity to a specific disease, ultimately protecting the person from that disease. Vaccines are commonly given via needle injections, but can also be distributed by mouth or sprayed into the nose.

The goal of vaccination is to prevent disease. The disease comes from a "pathogen" that could enter the body via a bacteria, virus, parasite, or fungus. Each pathogen contains its own specific antigen. Once a pathogen enters the body, the immune system begins to form antibodies to protect against the pathogen's specific antigen. Antibodies are proteins made by white blood cells as an immune response, and antibodies can bind specific antigens. Once bound, the antibody destroys the antigen. Some antibodies destroy antigens directly, while others make it easier for white blood cells to destroy the antigen. When the human body is exposed to an antigen for the first time, it takes time for the...