What are vaccines made of that help the body recognize and fight infections in the future?

Vaccines are primarily made from dead or weakened pathogens. These components are crucial because they stimulate the immune system without causing the disease that the pathogens would normally induce. By introducing a harmless version of the pathogen or a piece of it (such as a protein), the immune system is prompted to recognize it as a foreign invader and develop a memory of it.

This process results in the production of specific antibodies and the activation of T cells, which provide protection against the real pathogen if the body encounters it in the future. Dead or weakened pathogens mimic an infection, allowing the immune system to learn and prepare for future infections without the risk of full-blown disease. This mechanism is what makes vaccination an effective strategy in preventing infectious diseases.