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 immune system to respond and produce antibodies specific to that antigen.

Vaccines often contain weakened or inactive parts of a specific antigen and will trigger an immune response within the body. This weakened version will not cause the disease in the person receiving the vaccine, but it will prompt their immune system to respond much as it would have on its first reaction to the actual pathogen. Some vaccines take a different approach at the cellular level, affecting the RNA of the cells. Many vaccines can require multiple doses, given weeks or months apart. This is needed to allow for the recipient body's production of long-lived antibodies and development of memory cells. This way the body is trained to fight the specific disease-causing antigen, and it will create a memory of the pathogen so as to rapidly fight it if and when the body is exposed in the future.

Introduction to Vaccine History

Vaccination, the process of introducing weakened or inactivated material from an infectious organism or virus into a human body to train its immune response, has great importance in maintaining the public health of societies both domestically and abroad. In the past, vaccination was a hotly debated topic dominated by theories that could not fully explain...