What is the primary purpose of a vaccine?

The primary purpose of a vaccine is to prevent disease by stimulating an immune response. Vaccines are designed to introduce a harmless component of a pathogen, such as a protein or a piece of its genetic material, into the body. This exposure prompts the immune system to recognize and remember the pathogen, enabling it to mount a swift and effective response upon future encounters with the real pathogen. This proactive approach significantly reduces the risk of developing the disease that the vaccine is designed to protect against.

Vaccines do not treat existing infections or cure chronic diseases, as their function is preventive rather than therapeutic. Additionally, it is important to note that vaccines are not designed to eliminate all pathogens from the body; rather, they specifically aim to create immunity against specific diseases, thereby preventing infections caused by those pathogens.