A vaccine is a biological preparation designed to provide active acquired immunity against a specific infectious disease. It typically contains an agent that mimics a disease-causing microorganism and is often derived from weakened or inactivated forms of the microbe, its toxins, or a fragment of its surface proteins. This agent triggers the body’s immune system to recognize it as a threat, initiate a response to destroy it, and subsequently remember it, allowing the immune system to quickly identify and combat any similar microorganisms encountered in the future.Vaccines can be prophylactic, aiming to prevent or mitigate the effects of potential infections from natural or "wild" pathogens, or therapeutic, such as vaccines against cancer that are currently under research for treatment purposes.