The immune system is your body’s defence against invaders and attacks from outside; it helps to protect you and gives you the chance to recover. This system is divided into active and passive immunity as well as the innate immune system. These types of immunity can vary in strength across people but it works according to the same principles.
How Does the Immune System Work?
A major component of the immune system is identifying invaders when they show up. This job is typically performed by lymphocytes (a type of white blood cell). Messenger cells then send a distress signal across the body; this leads to new cells arriving at the site.
Phagocytes are a type of immune system cells that eat and destroy the invaders’ cells (whether bacteria, virus, or other parasites). The next step is when the immune system produces antibodies that continue fighting the infection. The antibodies are able to lock on to antigens (antigens are parts of viruses and bacteria that the immune system can latch on to).
These antibodies stick around long term, allowing the body to recognise the invader if it tries to attack you again. Now, let’s look at each of the categories under the classification of immunity types:
Types of Immunity
The different types of immunity perform complementary yet distinct jobs:
1. Innate Immunity
Innate immunity is the standard immunity we are all born with and it includes things like the skin (which is your first barrier against the entry of infections). This type of immunity involves physical barriers, cellular responses like attacking invading cells, inflammation (like getting a fever), and humoral response. The humoral response is when the body releases cells that can latch onto the membranes of bacterial cells and cause them to rupture. Tears and stomach acid are also part of the innate immune system.
2. Adaptive Immune System
Also known as active immunity, this is typically what most people think of when they hear the word ‘immune system’. This is a more targeted approach to fighting invaders. Whereas innate immunity is non-specific, adaptive immunity is highly specific to the invader. Adaptive immunity is regulated by T and B lymphocytes.
It takes a longer time for the body to mount the targeted response and in the end, memory cells store the information needed to fight the specific pathogen if it attacks again. Although this type of protection is not lifelong, in some cases and with certain pathogens, it can last your whole life. This is why people typically do not get smallpox twice.
3. Passive Immunity
This is a type of adaptive immunity that comes from an outside source. It is the manufacture of immune cells and subsequent addition into the body that sets this type of immunity apart. One of the most common passive immunity examples is when a foetus is in the womb, the mother is able to pass on antibodies to the child through the placenta.
The baby isn’t producing these immune cells but receiving them from the mother. A similar thing occurs after the baby is born during breastfeeding. Several antibodies are passed through the milk which helps the baby fight against bacterial infection (until the child can produce these defences themselves). Immune globulin transplants (derived from blood plasma) can be injected into a patient to provide a quicker immune response.
Role of Vaccines in Immunity
Through the power of science and medicine, we have been able to provide another layer of protection. Vaccines are a way to trick the immune system into learning how to fight a particular infection before you get infected. This may involve exposing the body to dead or harmless forms of the virus or bacteria, allowing the immune system to practice its defence.
Newer methods of vaccination allow the body to learn how to fight infections without ever exposing you to actual viral or bacterial parts. So, in addition to innate, passive, and adaptive types of immunity, we also have the power of vaccines on our side.
Conclusion
We hope you now have a fair idea of the different types of immunity. Whether it’s a fever or a full-blown viral infection, your body is trying its best to fight it with an arsenal of tools, ranging from proteins, antibodies, and chemicals and a multitude of organs. Keep in mind, this complicated system of systems is not perfect, an overactive immune system can lead to allergic reactions. And some people may develop an autoimmune disease, which is when the immune system mistakenly attacks the body.
Many things can play a role in your immune system’s ability to fight against pathogens effectively, including age, lifestyle, and genetics. If you are experiencing any sickness, then you can speak to a doctor and get treatment, since even our impressive immune systems may require a helping hand.
