When our immune system or immunity senses infections, it responds to the situation. Infections and illnesses can occur when the immune system is not activated. Problems such as allergic responses and autoimmune illness emerge when an immune system is aroused without a true threat or is not switched down when a threat has passed. Active immunity and passive immunity are two types of immunity.
Active Immunity vs Passive Immunity
The main difference between active immunity and passive immunity is that active immunity is a type of immunity that has developed in an individual’s body as a response to infections or with the help of vaccinations, whereas passive immunity is developed by transferring the antibodies for another individual through either placenta, breast milk, or injections.
Active immunity refers to a person’s body’s immediate response to infections. It is also induced when it is exposed to a foreign antigen, such as the antigen found in microorganisms. It also refers to a person’s adaptive reaction after coming into touch with a certain infection or antigen. This type of immunity does not develop instantly.
Passive immunity is immunity conferred by an individual through the transmission of serum or lymphocytes. They also get it from someone who is highly vaccinated. It also takes effect instantly and without delay. Furthermore, it is short-lived. In other words, it may only last a few months.
Comparison Table Between Active and Passive Immunity
| Parameters of Comparison | Active Immunity | Passive Immunity |
| Duration of Protection | Long-term | Short-term |
| Response Speed | Slow | Fast |
| Immunological Memory | It has an immunological memory. | It doesn’t have any immunological memory. |
| Antibodies | Produced in the body | Introduced from an external agent |
| Natural Acquirement | Infections | Through the placenta, breast milk |
| Artificial Acquirement | Vaccinations | Administration of antibodies through injections. |
| Immunity Type | Humoral and cell-mediated | Immunity is acquired through readymade antibodies. |
| Suitability | It is not suitable for immuno-compromised people. | It is suitable for immuno-compromised people. |
| Secondary Response | A faster and stronger secondary response. | No secondary response |
| Components | Antigen-presenting cells along with B and T cells | No immune cells included |
| Lag Period | Present | Absent |
| Side Effects | Generally, has no side effects | It May have some side effects |
What is Active Immunity?
Active immunity is immunity to a pathogen that develops after exposure to the infection. Immunity does not develop immediately after exposure to a pathogen. Active immunity can take days or weeks to develop following the first encounter.
When the body is exposed to a new disease agent, B cells, a kind of white blood cell, produce antibodies that aid in the destruction or neutralization of the pathogen. Antibodies are y-shaped proteins with the ability to attach to antigens on poisons or infections. Antibodies are disease-specific, which means they protect the body from only one type of disease agent.
Furthermore, the protection it provides is long-lasting. The protective response takes longer to build because of the lag period. Finally, a recurrence of infection or revaccination can reawaken it.
As a result, it could take days or weeks for it to manifest after the initial exposure. However, once it develops, the protection it provides can last a lifetime. Furthermore, it can occur in one of two ways: naturally or by immunization.
When a body is exposed to a disease, it develops its own antibodies, which is known as immunity. It enables the immune system to recognize a disease, which then prompts our bodies to fight it. It is frequently long-lasting, and it may provide us with disease protection for the rest of our lives.
What is Passive Immunity?
The antibody is produced without the involvement of immune cells in passive immunity. Furthermore, because it transmits directly, there is no antibody generation. Furthermore, memory immune cells do not form.
In addition, there is no alternative response available here. For continued protection, it must be re-administered on a regular basis. It’s then useful in cases of immune deficiency, immunodeficiency, or severe combined immunodeficiency.
Furthermore, it is a very useful way for giving resistance without having to wait for the active immune response to develop. It does not necessitate prior disease agent exposure.
It is a sort of immunity that is given to a person when they are given antibodies from outside sources. It gives temporary protection but not the long-term protection that active immunity provides.
Passive immunity can be acquired in a variety of ways and save one’s life. Because antibodies aren’t replaced as frequently as they are in someone whose immune system is responding in a very healthy and regular way, passive immunity is short-lived. Passive immunity can be acquired in a variety of ways like:
- Maternal antibodies: It can be in the form of transferring through the placenta and circulation during pregnancy and through breast milk after childbirth.
- Immunoglobulin treatments
Main Differences Between Active and Passive Immunity
- Active immunity gives your body long-term protection, whereas passive immunity gives your body short-term protection.
- The response speed of active immunity is slower than the response speed of passive immunity.
- Active immunity does not produce an immunological memory, whereas passive immunity does.
- The antibodies are produced in the body during active immunity, whereas in passive immunity, the antibodies are introduced from an external agent.
- Active immunity is acquired through exposure to infections naturally or through vaccinations, artificially. Passive immunity is acquired through the placenta or breast milk, naturally and through the administration of antibodies artificially.
- Active immunity is a humoral and cell-mediated immunity, whereas passive immunity is an immunity acquired through readymade antibodies.
- Active immunity is not suitable for immuno-compromised or immuno-deficient people, whereas passive immunity is suitable for them.
- Active immunity tends to have a faster and stronger secondary response, whereas passive immunity has no secondary response and needs to be re-administered.
- Active immunity has components consisting of antigen-presenting cells along with B and T cells. On the other hand, passive immunity has no immune cells.
- There is a lag period present in active immunity, whereas, in passive immunity, it is absent.
- Active immunity has no side effects usually. Passive immunity may have some side effects or reactions.
Conclusion
Our immunity offers us protection from external agents with the help of antibodies. Active immunity and passive immunity are two very important types of immunity in an individual’s life.
When our own immune system is in charge of safeguarding us from a pathogen, we are said to have active immunity. Active immunity can develop naturally or as a result of immunization.
When we are shielded from a pathogen by someone else’s immunity, we are said to have passive immunity.
References
- https://academic.oup.com/occmed/article-abstract/57/8/552/1474357
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2131512/