Summary of active and passive immunization

Active vs Passive Immunization (Simple &
Exam-Ready Notes for MLS Students)


Definition of Immunization

Immunization is the process by which an individual becomes protected against a disease through
the introduction of antibodies or stimulation of the immune system.


Active Immunization

Active immunization occurs when the body produces its own antibodies in response to exposure to
an antigen.

Examples: Vaccination such as measles vaccine, hepatitis B vaccine.

Characteristics:

- Slow onset of protection

- Long-lasting immunity

- Has memory (secondary response is faster and stronger)


Passive Immunization

Passive immunization occurs when pre-formed antibodies are transferred into the body.

Examples: Maternal antibodies (through placenta or breast milk), antiserum.

Characteristics:

- Immediate protection

- Short-lived immunity

- No immune memory


Differences Between Active and Passive Immunization

Active Immunization: Body produces antibodies, slow onset, long duration, memory present.

Passive Immunization: Antibodies are given, immediate onset, short duration, no memory.


Clinical Importance

- Active immunization is used for long-term disease prevention.