Explain what happens in the body when a Polio vaccine is administered.

The vaccine contains a weakened or inactivated form of the virus. The viral particle displays an antigen on its surface specific to poliovirus. Once in the blood, a specific helper T cell will detect the antigen by binding to it. The helper T cells will activate and stimulate specific B cells which divide rapidly by mitosis. Some B cells become plasma cells and secrete specific antibodies to destroy the pathogen as part of a primary immune response. Some B cells become memory cells which stay circulating in the blood. If poliovirus were to invade the body again the memory cells instantly recognise the antigen and initiate a fast and intense secondary immune response. The response Is so fast that the virus is eliminated before any symptoms are shown. The body now has artificial immunity against poliovirus