(a)How does a vaccine affect immunity?

(a)How does a vaccine affect immunity?
(b)How can we get immunized against tetanus?

(a)In vaccination, a preparation of antigenic proteins of pathogen or inactivated/weakened pathogen(vaccine is introduced into the body.The antibodies produced in the body against these antigens would neutalize the pathogenic agents during the actual infection.The vaccines also generate memory B and T cells.
(b)To create quick immune response as in tetanus we need to directly inject the preformed antibodies,${{O}_{1}}$ antitoxin( a preparation that is given to the toxin), and this type of immunization is called passive immunization.