Immunity can be defined as the body’s ability to defend against infections. Its a way of protecting the body against an infectious disease. As immune system recognizes an antigen, it attacks it. The phrase ‘immunity’ derives from the Latin immunitas, the felony fame of Roman city-states granted immunity from paying tributes to Rome or to people free of municipal duties; the foundation munis relating to alternate and (ex)changeable goods. This is the direct starting place of the criminal which means ‘immunity from prosecution’.

However, withinside the first century, Lucan (De Bello Civile) had already used the phrase metaphorically to explain the Psylli of North Africa as resistant to the bites of venomous snakes. Biological immunity can check with constitutive bodily innate mechanisms, which include the bodily safety afforded towards contamination via way of means of the skin. The interest of herbal killer (NK) cells towards virus-inflamed cells or the herbal resistance of mice to diphtheria toxin due to the absence of a receptor for that toxin.

Immunity also can be innate however inducible, as withinside the antiviral country prompted via way of means of publicity to double-stranded RNA (dsRNA). Finally, immunity to precise microbes may be obtained throughout the life of the person via way of means of contamination or vaccination.


Immune System

The origins of immunology as technological know-how are misplaced in antiquity however have usually been basically linked with microbiology. It changed into without a doubt recognized earlier than the start of the Common Era that survivors of sure plagues (possibly smallpox) had been resistant to its recurrence.

Observations which include those had been rendered unsure via way of means of vague diagnoses of the illness. However, superior sufficiently in order that via way of means of the cease of the primary millennium, Common Era, Chinese and Hindu healers had been privy to the efficacy of the homoeopathic exercise of insufflation, wherein powdered scabs of the stricken had been blown via straws into the lungs of wholesome people.

This statement drew those historic medical doctors to an essential perception on obtained immunity – a few belongings of the diseased ought to set off long-status and precise safety in naive people. Centuries of observations and reconceptualizations approximately the specificity of this safety caused Fracastoro’s fourteenth-century germ idea of infectious disease, which held that infectious illnesses had been due to disease-precise agents.

How does the immune machine work?

When the frame senses overseas substances (referred to as antigens), the immune machine works to understand the antigens and cast off them.

B lymphocytes are brought about to make antibodies (additionally referred to as immunoglobulins). These proteins lock onto precise antigens. After they are made, antibodies normally live in our bodies in case we need to combat the equal germ again. That’s why a person who receives ill with a disease, like chickenpox, normally might not get ill from it again.

This is likewise how immunizations (vaccines) save you a few illnesses. An immunization introduces the frame to an antigen in a manner that does not make a person ill. But it does permit the frame to make antibodies on the way to shield the individual from destiny assault via way of means of the germ.

Although antibodies can understand an antigen and lock onto it, they can not spoil it without assistance. That’s the activity of the T cells. They spoil antigens tagged via way of means of antibodies or cells which are inflamed or one way or the other changed. (Some T cells are truly referred to as “killer cells.”) T cells additionally assist sign different cells (like phagocytes) to do their jobs.

Antibodies additionally can neutralize toxins (toxic or detrimental substances) produced via way of means of specific organisms. Antibodies normally live in our bodies in case we need to combat the equal germ again. That’s why a person who receives ill with a disease, like chickenpox, normally might not get ill from it again. Set of proteins referred to as supplements which are a part of the immune machine. Complement facilitates killing bacteria, viruses, or inflamed cells. These specialised cells and elements of the immune machine provide the frame safety towards disease. This safety is referred to as immunity.

Three kinds of immunity in humans

  • Innate immunity: Everyone is born with innate (or natural) immunity, a type of general protection. For example, the skin acts as a barrier to block germs from entering the body. And the immune system recognizes when certain invaders are foreign and could be dangerous.
  • Adaptive immunity: Adaptive (or active) immunity develops throughout our lives. We develop adaptive immunity when we’re exposed to diseases or when we’re immunized against them with vaccines.
  • Passive immunity: Passive immunity is “borrowed” from another source and it lasts for a short time. For example, antibodies in a mother’s breast milk give a baby temporary immunity to diseases the mother has been exposed to.

The immune system takes a while to develop and needs help from vaccines. By getting all your child’s recommended vaccines on time, you can help keep your child as healthy as possible.

Function Passive and Active Immunity

Immunity to a disease is achieved through the presence of antibodies to that disease in a person’s system. Antibodies are proteins produced by the body to neutralize or destroy toxins or disease-carrying organisms. Antibodies are disease-specific. For example, a measles antibody will protect a person who is exposed to measles disease but will have no effect if he or she is exposed to mumps.

Active Immunity

Active Immunity results when exposure to a disease organism triggers the immune system to produce antibodies to that disease. It can be acquired through natural immunity or vaccine-induced immunity.

Natural immunity is acquired from exposure to the disease organism through infection with the actual disease. Vaccine-induced immunity is acquired through the introduction of a killed or weakened form of the disease organism through vaccination. Either way, if an immune person comes into contact with that disease in the future, their immune system will recognize it and immediately produce the antibodies needed to fight it. Active immunity is long-lasting, and sometimes life-long.

Passive Immunity

Passive immunity is provided when a person is given antibodies to a disease rather than producing them through his or her own immune system. A newborn baby acquires passive immunity from its mother through the placenta. People can also get passive immunity through antibody-containing blood products such as immune globulin, which may be given when immediate protection from a specific disease is needed.

The major advantage of passive immunity is that protection is immediate, whereas active immunity takes time (usually several weeks) to develop. However, passive immunity lasts only for a few weeks or months. Only active immunity is long-lasting.

FAQs about Immunity

Q.1:  How many kinds of immunity can be seen in humans?

Ans: Three kinds of immunity can be seen in humans specifically; active, passive and innate immunity.

Q.2: How can someone boost his/her immunity?

Ans: Every part of the body or say your immune system works, even more, better if protected from the environmental assaults hence eat a healthy meal and avoid smoking or any such health-hazardous things.

Q.3: Where are antibodies found?

Ans: Antibodies normally live in our bodies in case we need to combat the equal germ again. That’s why a person who receives ill with a disease, like chickenpox, normally might not get ill from it again. Set of proteins referred to as supplements which are a part of the immune machine.

Share with friends

Customize your course in 30 seconds

Which class are you in?
Get ready for all-new Live Classes!
Now learn Live with India's best teachers. Join courses with the best schedule and enjoy fun and interactive classes.
Ashhar Firdausi
IIT Roorkee
Dr. Nazma Shaik
Gaurav Tiwari
Get Started

Leave a Reply

Your email address will not be published. Required fields are marked *

Download the App

Watch lectures, practise questions and take tests on the go.

Customize your course in 30 seconds

No thanks.