What type of immunity is primarily achieved through vaccinations?

The correct answer is that vaccinations primarily achieve active immunity. Active immunity occurs when the immune system is exposed to a pathogen (or parts of a pathogen, such as proteins or sugars) and responds by producing specific antibodies. When a person receives a vaccination, they are introduced to inactivated or weakened forms of the pathogen or its antigens. This triggers the immune system to produce a response, and memory cells are developed that “remember” how to fight off the pathogen if encountered in the future.

Natural immunity, on the other hand, develops through exposure to the actual disease-causing pathogen. Passive immunity involves the transfer of antibodies from one individual to another, such as from mother to child during pregnancy or through breast milk, and does not involve the recipient's immune system creating a response. Herd immunity refers to the protection that occurs when a sufficient portion of a population is immunized against a contagious disease, thereby reducing its spread. While these concepts are all related to immunity, active immunity specifically pertains to the direct response from the immune system that is stimulated by vaccinations.