Immunization it is the acquisition of immunological protection against an infectious disease, which can be active or acquired.
Active Immunization
It occurs when the individual's own immune system comes into contact with a substance that is foreign to the body and responds by producing antibodies and T lymphocytes.
This type of immunity usually lasts for several years or until the end of life. Active immunity can be acquired by contracting an infectious disease or by taking a vaccine.
Passive Immunization
Passive immunization is the transfer of antibodies produced by an animal or another person. It produces fast and efficient protection, but temporary, lasting a few weeks or months, on average.
The most common type of passive immunity is natural passive immunity that occurs through the passage of antibodies from the mother to the fetus through the placenta in the last 2 months of pregnancy, giving the child good immunity in its first year of life.
Artificial passive immunity can be acquired in 3 main ways:
- Combined human immunoglobulin;
- Hyperimmune human immunoglobulin;
- Heterologous serum.
Blood transfusion is also a way to acquire passive immunity, as all types of blood products contain antibodies.
See also: meaning of Immunity.
