What is the purpose of adjuvants in vaccines?

Adjuvants are substances that are added to vaccines to enhance and strengthen the body's immune response to the provided antigen. Their primary purpose is to stimulate and enhance the immune system's reaction, making the vaccine more effective at generating immunity. By improving the body's ability to recognize and respond to the antigen, adjuvants can help ensure that the immune response is strong enough to provide long-lasting protection against the targeted disease.

The correct answer emphasizes that adjuvants not only bolster the immune response but also potentially reduce the need for additional doses of the vaccine. This capability is particularly important for vaccines that use weaker forms of antigens, as it can ensure adequate immune defense without overwhelming the body.

In contrast, other options misrepresent the role of adjuvants. For example, adjuvants do not decrease the immune response or act primarily as preservatives; those roles are fulfilled by other compounds in vaccine formulations. Additionally, while some vaccines may not require boosters due to the effectiveness of adjuvants, this is not the primary function of adjuvants themselves.