A weakened or dead form of influenza is injected into the patient. However, the pathogen will not cause harm as it is not strong enough to do so. The weakened form of influenza will stimulate the immune response.
B-cells detect that there is an unknown substance in the body and they are sent to where the weakened form of influenza that has been injected. The antigen will bind to the b-cell receptor, meaning the b-cells have detected a foreign substance in the immune system
The B-cells produce antibodies that are specific to the antigen (influenza). These antibodies slow down the virus of influenza which allows phagocytes (white blood cells) to engulf the the virus. The phagocytes engulfing the antigen is a non specific defence mechanism
The weakened form of influenza is no longer able spread throughout body meaning it will be easier contain and destroy.
Memory B-cells are formed to detect which antibodies are most effective when it comes to fighting the same pathogen. This is a specific defence mechanism These antibodies will be be better equipped to fight influenza if faced by it again.
The vaccine has successfully created artificial immunity to influenza and has been used as a training session for the immune system.