Difference between Herd Immunity and Natural Immunity

Before learning about the difference between Herd Immunity and Natural Immunity let us get some knowledge about Immunity and its types.

Immunity can be termed as a body’s defense mechanism against foreign elements. In other words, the ability to fight/resist a pathogen depends on your immune system. There are mainly two types of Immunity which include active and passive immunity.

Active Immunity: Active Immunity is developed after being exposed to an infection or getting a vaccine.

Passive Immunity: Passive Immunity is acquired from an external body (Someone or something) such as from maternal antibodies.

Active Immunity is subdivided into two categories: Natural and Artificial.

Natural Immunity: Immunity developed over time by exposure to infection/virus can be called natural immunity.
Artificial Immunity: The Antibodies generated after vaccination are an artificial method of Immunity generation.

Passive Immunity is also subdivided into two categories: Natural and Artificial.

Natural Immunity: It is acquired naturally such as the fetus gets antibodies from the mother.
Artificial Immunity: It is acquired from serum or plasma, which contains antibodies.

A clear image of Active and Passive immunity is explained well in the above image.

Having had a brief idea of what Immunity is and its types, Let us see what Herd Immunity is:

Herd Immunity

The word “Herd Immunity” can be divided into two parts “Herd” meaning a large group of animals or mammals, and “Immunity” meaning an ability to resist an infection or toxin. The word combined would mean a group of people having the ability to resist something (an infection or a disease).

Herd Immunity is a process to develop immunity in a large number of people so as to reduce the chances of the people with less Immunity getting infected by the virus/disease.

This practice was followed for the eradication of smallpox. In this process, a large number of people are vaccinated instead of directly getting them in contact with the pathogen, creating a Herd Immunity situation. Let us take a look at the following image for a better understanding.

As you can see that in the above figure purple man is denoted as healthy and non-vaccinated, yellow man is denoted as vaccinated and healthy, red man is denoted as contagious and non-vaccinated.

In the first scenario, only two to three people are vaccinated and two are seen to be contagious. In this case, the virus will spread massively as there is no immunization.

In the second scenario, a whole bunch of people is vaccinated, one is contagious and two to three are healthy non-vaccinated people. In this scenario, mass spreading does not occur as there are a lot of people who are immunized hence forbidding the spread of the virus.

We can take the example of COVID-19. In the current ongoing scenario, we are trying to achieve Herd Immunity by vaccination process.

Natural Immunity

Simply stated, natural immunity is the existing immunity of our body. The human body is capable of developing antibodies for any viruses or bacteria that might be harmful to our body. Natural immunity is powerful as a subject is exposed to a large number of bacteria/viruses. This results in a stronger response to the excessive dose of microbes. A healthy immune system can detect a majority of viruses and can defend against them, but for Immuno-suppressed people, the virus detection may be slow causing the infection to be long-term.

The major setback of Natural Immunity is that you will never know how serious a virus infection can be. Taking the example of COVID-19 a survey shows that some people were not affected much because of the virus, mere home treatments worked for them while others got serious and had to be admitted. Some were unfortunate enough to lose their life.

Is natural immunity better than vaccinated immunity?

This question would have no solid ground as in some cases natural Immunity has turned out to be much stronger than vaccinated immunity. Example: mumps. While in other cases vaccinated Immunity has turned out to be a better choice, for example: COVID-19.