How Do Vaccines Elicit a Targeted Immune Response?
Vaccines work by introducing an antigen, which is a molecule that the immune system can recognize as foreign. This can be in the form of a weakened or inactivated pathogen, a piece of the pathogen (such as a protein), or a viral vector carrying pathogen genes. Upon vaccination, the immune system mounts a response, generating [antibodies]( ) and [memory cells]( ) that remain in the body long-term. These memory cells enable the immune system to quickly and effectively respond if it encounters the pathogen again.
