Inactivated Vaccines

Inactivate vaccines, also known as killed vaccines, are an important part of the arsenal we wield against the plethora of different infectious agents we encounter every day. Many key immunisation programmes rely heavily on this particular type of vaccination as well as others, and in this article we look at what exactly inactivated vaccines are, and how they achieve our immunisation goals.

Inactivated vaccines

Like all vaccines, the purpose of an inactivated vaccination is to confer immunity against a particular disease causing microbe, and in doing so prevent serious and often highly contagious illnesses. Unlike live vaccinations which carry weakened but very much living microbes, or toxoid vaccines which carry harmless versions of toxic compounds released by microbes, an inactivated vaccine is composed of the remains of viruses or bacteria that have been killed.

An inactivated microbe doesn’t pose any risk to the person receiving the vaccine because a dead microbe can’t take any action against the body, this makes this particular type of vaccination very safe. Despite being dead however, the microbe can still induce an immune response, which is the whole point of a vaccination. The molecules on the surface of the microbe that your body recognises as a threat are still intact, meaning that your immune system is able to develop a defence against the microbe, ultimately resulting in immunity should you encounter the live virus or bacteria at any point.

Why use inactivated vaccines?

This type of vaccination offers a number of distinct benefits, not the least of which is safety. Many people are far more comfortable with the idea of this type of vaccination than alternatives like the live vaccine, which involves the administration of a weakened but living form of a microbe. An inactivated vaccine is much more stable than the live alternative, and doesn’t carry any risk of reverting back to a virulent state.

Inactivated vaccines also don’t require low temperatures for storage, a condition which can be hard to maintain when shipping large quantities of this treatment across the world. Particularly to impoverished countries where the storage facilities needed to preserve live vaccines (which have to be refrigerated) would be lacking.

Inactivated vaccines are less effective than alternatives like the live vaccine however, and this is because in an inactivated state a microbe can’t induce the immune response as effectively as a live virus or bacterium can. This means that booster shots on a set immunisation schedule are needed to confer and maintain immunity against the disease in question.

What are examples of inactivated vaccines?

Inactivated vaccines are used for protection against a number of different conditions, both bacterial and viral. Examples of viral conditions include a particular polio vaccine called the Salk vaccine and the flu vaccination. Bacterial examples include injections against cholera, pertussis, and typhoid.

Having the option of preparing and delivering inactivated vaccination is important as different immunisation technologies help us combat the huge variety of microbes we face in the world around us. In some cases inactivated vaccines are far more effective than other technologies, and can be delivered to more people, particularly pregnant and immunocompromised patients who wouldn’t be able to safely take live vaccines.

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