How do subunit vaccines work?

Subunit vaccines work by introducing a harmless piece of the pathogen to stimulate an immune response.

Subunit vaccines are a type of vaccine that only use specific parts of the pathogen to stimulate an immune response. These parts can be proteins or sugars from the pathogen. The idea is to select the most harmless yet most immune-stimulating parts of the pathogen. This way, the immune system can learn to recognise and respond to the pathogen without the risk of causing disease.

The process of creating a subunit vaccine involves identifying the right antigen (the part of the pathogen that triggers an immune response) and then producing it in large quantities. This can be done through genetic engineering, where the genes for the antigen are inserted into another organism, like yeast, which then produces the antigen. Alternatively, the antigen can be produced synthetically in a lab.

Once the antigen is introduced into the body through the vaccine, the immune system recognises it as foreign and mounts an immune response. This involves producing antibodies, which are proteins that can recognise and bind to the antigen. The immune system also produces memory cells, which remember the antigen and can mount a faster and stronger response if the pathogen is encountered again in the future.

Subunit vaccines have several advantages. They are very safe, as they cannot cause the disease they are designed to protect against. They can also be used in people with weakened immune systems, who may not be able to handle live vaccines. However, they often require booster shots to maintain immunity, as the immune response they stimulate is not as strong or long-lasting as that from live vaccines.

In summary, subunit vaccines work by introducing a harmless piece of the pathogen to the immune system. This stimulates an immune response, including the production of antibodies and memory cells, which can protect against future infection.