Difference between active immunity and passive immunity
La immunity It is the body's ability to defend itself against pathogens such as viruses, bacteria and other microorganisms that can cause disease. There are two main types of immunity: active immunity and the passive immunity. Understanding the difference between these two types of immunity is essential to understand how our body protects itself against infections.
La active immunity It develops when our own immune system produces antibodies specific to combat a specific pathogen. This type of immunity can be acquired naturally, by exposure to an infectious agent, or artificially, through vaccination. Active immunity is long-lasting and can provide long-term protection against future infections with the same pathogen.
Acquisition of active immunity
Active immunity can be acquired in two main ways:
- natural infection: When a person is exposed to an infectious agent and becomes sick, their immune system produces specific antibodies to fight the infection. Once the person recovers, these antibodies remain in the person's body, providing protection against future infections by the same pathogen.
- Vaccination: Vaccines contain weakened or inactivated versions of pathogens, or parts of them, that stimulate the immune system to produce antibodies without causing disease. Vaccines induce an immune response similar to that of a natural infection, but without the risks associated with the disease.
On the other hand, the passive immunity It is acquired when a person receives antibodies produced by another organism. These antibodies can come from the mother (through the placenta or breast milk) or from medical products such as immunoglobulin. Passive immunity provides immediate protection, but is short-lived, since antibodies are not produced by the body itself and degrade over time.
Sources of passive immunity
There are two main sources of passive immunity:
- Maternal transfer: During pregnancy, the mother transfers antibodies to the fetus through the placenta, providing protection to the newborn during the first months of life. Additionally, breast milk also contains antibodies that help protect the baby against infections.
- Medical products: In some cases, specific antibodies can be administered through medical products such as immunoglobulin. These products are used to provide immediate protection against certain diseases or to treat specific conditions.
Comparison between active and passive immunity
| Feature | Active immunity | Passive immunity |
|---|---|---|
| Antibody production | Produced by the body itself | Received from another source |
| Duration of protection | Long-term (years or lifetime) | Short duration (weeks or months) |
| Start of protection | Requires time to develop | Provides immediate protection |
| Acquisition mechanism | Natural infection or vaccination | Maternal transfer or medical products |
In short, active immunity It develops when the body itself produces antibodies in response to an infection or vaccination, while the passive immunity It is acquired by receiving antibodies from another source. Both types of immunity play an important role in protecting against infectious diseases, but differ in their duration and mechanism of action.
Understanding the difference between active and passive immunity is essential to making informed decisions about prevention of diseases and health care. Vaccination, as a method of acquiring active immunity, is a fundamental tool in the fight against many infectious diseases and has saved millions of lives around the world.