What type of immunity is provided by vaccines?

Vaccines provide artificially active immunity. This type of immunity is created when a person is exposed to a harmless form of a pathogen or its components (like proteins) through vaccination. The immune system responds by producing its own antibodies and activating memory cells that prepare the body to respond more effectively if it encounters the actual pathogen in the future.

Artificially active immunity differs from natural active immunity, which occurs when a person is exposed to a disease-causing pathogen through natural infection and subsequently develops immunity after recovering from the illness. In contrast, natural passive immunity involves antibodies being transferred from mother to child, such as through breast milk, providing temporary protection. Artificial passive immunity, on the other hand, involves the direct transfer of antibodies from one individual to another, for instance through injections of antibody-containing serum.

This distinction is important in understanding how vaccines operate to provide long-term immunity and how they differ from natural infection or other forms of immunity.