What Is A Vaccine?

A living organism such as the body has the power itself to resist and overcome infections. This is known as immunity. The body has to be helped to acquire this immunity. In this case of many diseases produced by viruses, immunity is created by a person's having the disease and recovering from it. As an example chicken pox give the body a lasting immunity, means once someone have this disease, he won't get that again.

To produce immunity artificially, a virus can be injected that has been weakened. The person thus gets a slight case of the disease. When he recovers, he remains immune for various lengths of time. The injection of the weakened virus is known as vaccination. A vaccine consists of the disease organisms which have been made harmless and produce immunity by causing the formation of antibodies. Antibodies neutralized the viruses and are produced by the body itself. The vaccine fuels the body to produce them.

A vaccine is a medical preparation given to a person to provide immunity from a disease. Vaccines use a variety of different substances ranging from dead microorganisms to genetically engineered antigens to defend the body against potentially harmful antigens. Effective vaccines change the immune system by promoting the development of antibodies that can quickly and effectively attack disease causing microorganisms or viruses when they enter the body, preventing disease development.