In the active immunization (Active vaccination) is the classic vaccine with a vaccine containing antigens.
A live vaccine (severely attenuated pathogen) or a dead vaccine (killed pathogen) is administered intramuscularly (in the muscle), subcutaneously (tissue under the skin), or as a vaccine and induces an immune response. It comes to the formation of antibodies against the antigens of the vaccine. This process can take one to four weeks before the antibody circulates in the immune system.
Once the pathogen comes into contact with the immune system again, memory cells recognize the antigens and force the immediate formation of the specific antibodies. Because of the immediate immune response, the multiplication of the pathogen can be stopped in time, so that the infectious disease does not break out.
The counterpart to active immunization is passive vaccination or passive immunization.