A vaccine is a biological preparation that improves immunity to a particular disease. Vaccination is the administration of antigenic material to stimulate an individual’s immune system to develop adaptive immunity towards a pathogen. The terms vaccine and vaccination are derived from Variolae vaccinae to denote cow pox, the term devised by Edward Jenner.
A vaccine typically contains an agent that resembles a disease-causing microorganism, and it often made from weakened or killed forms of the microbe, its toxins or one of its surface proteins. Some vaccines contain inactivated micro-organisms that have been destroyed with chemicals, heat, radiation, or antibiotics ex., like influenza, cholera, bubonic plague, polio, hepatitis A, and rabies.
Immunotechnology, is an important arm of biotechnology, constituting the industrial scale application of immunological procedures to produce vaccines, for mass immunisation to prevent prevalent diseases and/or producing immunological therapeutic agents to cure the afflicted. Production of protein vaccines has been in large-scale use for a long time and the current trend is to develop the more specific DNA vaccines.
The agents stimulating the body’s immune system to recognize the agent as a threat, destroy it, and keep a record of it, so that the immune system can more easily recognize and destroy any of these microorganisms that it later encounters. The immune system recognizes vaccines as foreign, destroys them, and “remembers” them. When the virulent version of an agent is encountered, the body recognizes the protein coat on the virus, and thus is prepared to respond, by (1) neutralizing the target agent before it can enter cells, and (2) recognizing and destroying infected cells before that agent can multiply to vast numbers. A number of other vaccine strategies are under experimental investigation that includes DNA vaccination and recombinant viral vectors The World Health Organization (WHO) has report that licensed vaccines are currently available to prevent and control the infections. Proponents say that vaccination is safe and one of the greatest health developments of the 20th century.