What is the role of vaccines in immunity?

• A. They provide passive immunity by transferring antibodies.
• B. They expose the immune system to antigens to generate memory without causing disease.
• C. They stimulate fever to fight pathogens.
• D. They suppress the immune system.

Answer: (B)

Vaccines train the immune system to recognize pathogens by presenting it with antigens in a safe way, which stimulates an adaptive immune response and creates memory B and T cells. This memory allows a faster, stronger defense if the real pathogen is encountered later, often preventing disease or reducing its severity without the person actually getting sick. That’s why the best description is that vaccines expose the immune system to antigens to generate memory without causing disease.

Transferring antibodies from another person or source provides immediate but temporary protection, which is not how vaccines work. Fever can occur after vaccination as a short-term reaction, but it isn’t the role of vaccines to induce fever or to drive protection. Suppressing the immune system would undermine the goal of vaccination.