Subunit Vaccine

In order to safely and effectively immunise the public against the many different viruses and bacteria we encounter every day, new vaccination technologies are constantly being researched for future use. Vaccinations have become the bedrock of preventative medicine in the world today, and their benefits aren’t just limited to the health advantages of limiting the spread of dangerous diseases, they extend to the fact that by preventing disease in the first place healthcare becomes more cost-effective and efficient.

In this article we look at a more recent type of vaccine, the subunit vaccine, and why it has been developed for use in routine immunisation schedules across the world.

Why have Subunit Vaccines been developed?

Vaccines are carefully studied for their safety and effectiveness prior to their use, and as this is the case, vaccinations applied for public use are known to be safe as well as effective. That being said, certain types of vaccination currently in use do carry with them some inherent risks. Live, attenuated vaccines for example carry a risk of reversion, which happens when the weakened strain used for vaccination changes into a more virulent and harmful version of the disease. Reversion is a concern when using these vaccinations, and is one of the reasons why alternatives like the subunit vaccine have been developed.

Another safety concern, again with live vaccines, is the fact that the attenuated strain of virus or bacteria mimics an actual infection in some ways. While this is also an advantage because this action stimulates a strong immune reaction, it poses a risk to people in vulnerable states of health like the elderly or pregnant women.

Subunit vaccines successfully overcome these risks as fragments of a disease causing pathogen are used rather than the whole organism. These subunits are carefully selected for their capacity to stimulate the body’s defences and thereby immunise an individual against disease.

Viruses and bacteria have specific structures on their surfaces which our body is capable of identifying as markers of disease. By isolating these fragments, purifying them, and placing them in a vaccine we can create safe vaccines that circumvent many of the risks posed by other vaccination types.

What subunit vaccines are being used?

At present the best example of a subunit vaccine in regular use is the hepatitis B immunisation. This is made by inserting the genetic material coding for particular subunits of the hep B virus into everyday yeast, which then expresses these genes and produces subunits for purification and later use. This is a process called genetic recombination, and is a successful method of generating large quantities of vaccine in dedicated manufacturing facilities.

Subunit vaccines are being tested for hepatitis C, the whooping cough, and herpes simplex.

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