Immunity
Q. 1. Define and classify immunity
Ans. Immunity is defined as state of resistance of a host to pathogens and their
toxic products. It is of two types:
1. Innate immunity (Species, Racial, Indiviual)
a) Non-specific
b) Specific
2. Acquired Immunity
a) Active
• Natural
• Artificial
b) Passive
• Natural
• Artificial
Q. 2. Tabulate differences between active and passive immunity
Active Immunity Passive immunity
• Produced actively by host’s • Received passively by the host.
immune system as a result of No participation of host’s
antigenic stimulation immune system.
• Induced by infection or by • Conferred by administration of
contact with antigens antibodies.
• Long lasting • Transient
• Immunity effective only after a • Immunity effective immediately.
lag period. i.e, time required for
generation of antibodies and
immunocompetent cells.
• During development of active • No negative phase
immunity there is often a
negative phase during which
the level of measurable
immunity may actually be
lower than before antigenic
stimulus.
• This is due to antigen
combining with the pre-existing
Q. 1. Define and classify immunity
Ans. Immunity is defined as state of resistance of a host to pathogens and their
toxic products. It is of two types:
1. Innate immunity (Species, Racial, Indiviual)
a) Non-specific
b) Specific
2. Acquired Immunity
a) Active
• Natural
• Artificial
b) Passive
• Natural
• Artificial
Q. 2. Tabulate differences between active and passive immunity
Active Immunity Passive immunity
• Produced actively by host’s • Received passively by the host.
immune system as a result of No participation of host’s
antigenic stimulation immune system.
• Induced by infection or by • Conferred by administration of
contact with antigens antibodies.
• Long lasting • Transient
• Immunity effective only after a • Immunity effective immediately.
lag period. i.e, time required for
generation of antibodies and
immunocompetent cells.
• During development of active • No negative phase
immunity there is often a
negative phase during which
the level of measurable
immunity may actually be
lower than before antigenic
stimulus.
• This is due to antigen
combining with the pre-existing
