A vaccine is a biological preparation that provides active acquired immunity to a particular disease. A vaccine typically contains an agent that resembles a disease-causing micro-organism and is often made from weakened or killed forms of the microbe, its toxins are one of its surface proteins. The agent stimulates 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 micro-organisms that it later encounters. Emerging practices and the experiences in this field needs a critical and thorough discussion to spread the knowledge so that the researchers adopt them to pass on the benefits to the needy. Vaccines and Immunization as a field of research has been the centre of an intense debate for many years now. They have helped save countless lives and are the reason some of the most deadly diseases in the world have been completely eradicated. There have also been many misconceptions regarding the efficiency of vaccines, and whether they have any harmful effects. There are several aspects to this research, and thousands of researchers are exploring every possible avenue in the hope of helping the world get rid of even more diseases.