The type of vaccine that is given to humans to protect them from becoming infected with a virus that causes a particular disease may contain

The principle of immunization or vaccination is based on the immune system's memory property. Vaccination involves injecting a preparation containing pathogen antigenic proteins or an inactivated/weakened pathogen (vaccine) into the body. During an infection, antibodies created in the body against these antigens would neutralize the pathogenic agents. The vaccine also produces memory B and T cells, which recognise the virus quickly upon subsequent exposure and overpower the invaders with huge antibody production.