Vaccination, Immunisation & Artificially Acquired Immunity

While our bodies possess a potent defensive mechanism that works to protect us from infection on a day to day basis, there are times when it needs some help to keep us healthy. Some conditions can devastate us before we have a chance to defend against it, and that’s where the field of immunisation comes in. Immunisation stems from the idea of providing your body with immunity from particularly potent diseases, however there are a lot of technical terms which can be confusing in this area. This article looks at three key terms, vaccination, immunisation, and artificially acquired immunity and what they mean, arming you with the knowledge you need to understand the area if you are looking into it.

What is vaccination?

Vaccination is actually a very specific term referring to a treatment which is readily available from health services across the world. A vaccine is designed to expose an individual to a weakened virus or bacteria, or to elements of that virus or bacteria, and through that induce a response from the body’s natural defensive mechanisms. By doing this the body’s immune system (the defensive system responsible for maintaining our health) is effectively primed and ready for further exposure to the infectious agent.

What is immunisation?

The words ‘immunisation’ and ‘vaccination’ are often used interchangeably, however the two terms mean different things. While a vaccination is an individual treatment designed to confer immunity against a particular condition, immunisation is used as a broader term to describe populations or communities. Immunisation is often used in the context of describing ‘immunisation’ programmes for example, whereas a vaccination will be a single treatment to an individual.

Moreover immunisation means that immunity has been conferred, which means that your body is protected against a disease and its incidence. Vaccinations however, do not necessarily guarantee immunity. While the effectiveness of vaccines is extremely high, and this is evidenced by the rapid decline in the incidence of diseases after they have been vaccinated against, they do not guarantee immunity against a condition. 

What is artificially acquired immunity?

Artificially acquired immunity describes any and all immunity conferred by artificial means. Naturally conferred immunity requires no human intervention, and simply involves becoming exposed to a condition and your body’s natural immune mechanisms kicking into confer protection against that particular disease causing agent. Our bodies learn how to defend against diseases after being exposed to them, and this natural defence mechanism is key to our survival in a world full of a huge variety of different infectious agents.

Artificially acquired immunity is conferred without exposure to the actual virus or bacteria responsible for the disease. Instead, a specially prepared version of the disease causing agent (pathogen) or parts of it are provided to stimulate your body’s defences.

What is an inoculation?

An inoculation is in some ways a very primitive vaccination procedure. But while vaccines come in a range of different formulations and are specially devised and produced, an inoculation involves taking an unaltered live pathogen (which usually confers a mild form of a disease) and using that in the same way. This can be riskier, and isn’t broadly used as the application is more limited than vaccination.

The classic example of inoculation is exposure to cowpox to immunise someone against smallpox.

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