The vaccine prepares you to not keep the infections available. The vaccine contains an agent such as a microorganism that causes disease and is usually made from weak or killed microbe species, its toxins, or one of the surface proteins. The agent stimulates the immune system to recognize the agent as a threat, to destroy it, and to monitor and destroy any small objects that the agent may encounter in the future. Vaccines can be prophylactic, or therapeutic.

Vaccination management is called vaccination. Vaccination is the most effective way to prevent infectious diseases; The immunity due to vaccination contributes to the global eradication of smallpox and the prevention of diseases such as polio, measles, and tetanus in much of the world. The effectiveness of the vaccine has been widely studied and validated; for example, vaccines that have proven to be effective include the flu vaccine, the HPV vaccine, and the chicken vaccine. The World Health Organization (WHO) reports that currently licensed vaccines are currently available for twenty-five chronic diseases.