Which of the following is NOT a characteristic of pure polysaccharide vaccines?

The statement that pure polysaccharide vaccines activate B cells is appropriate because these vaccines are specifically designed to stimulate the immune response, primarily through the activation of B cells. When administered, pure polysaccharide vaccines lead to the production of antibodies by B cells, which are crucial for the immune defense against encapsulated bacteria.

In addition, pure polysaccharide vaccines typically do not provide long-lasting immunity due to their inability to effectively stimulate T cell responses, which are necessary for generating immunological memory. This contributes to the shorter duration of immunity compared to conjugate vaccines, which can induce both B cell activation and a robust T cell response.

Moreover, pure polysaccharide vaccines are often used for particular pathogens, usually encapsulated bacteria, indicating a targeted approach in immunization. This specificity is essential in strategic vaccination programs.

The choice indicating that pure polysaccharide vaccines do not activate B cells is incorrect because it undermines the primary function of these vaccines. The correct understanding of how these vaccines work underscores their role in eliciting an immune response through B cell activation, despite their other limitations.