How do adjuvants work in vaccinations?

Adjuvants enhance the body's immune response to an antigen in a vaccine.

Adjuvants are substances that are added to vaccines to boost the body's immune response to the antigen, which is the substance in the vaccine that triggers the immune response. They work by stimulating the immune system to respond more vigorously to the antigen, thereby increasing the effectiveness of the vaccine.

The immune system's response to an antigen can be divided into two main types: the innate immune response and the adaptive immune response. The innate immune response is the body's first line of defence against pathogens. It is a general response that is not specific to any particular pathogen. The adaptive immune response, on the other hand, is a specific response to a particular pathogen. It involves the production of antibodies that are specifically designed to neutralise that pathogen.

Adjuvants work by stimulating the innate immune response, which in turn enhances the adaptive immune response. They do this by activating immune cells such as macrophages and dendritic cells, which play a key role in the innate immune response. These cells recognise the adjuvant as a foreign substance and respond by producing inflammatory signals. These signals attract other immune cells to the site of the vaccination, thereby increasing the immune response to the antigen.

In addition to enhancing the immune response, adjuvants also help to prolong the immune response to the antigen. This is important because it allows the immune system more time to produce antibodies against the antigen. Furthermore, by prolonging the immune response, adjuvants can help to ensure that the immune system 'remembers' the antigen. This means that if the body is exposed to the same antigen in the future, it can mount a quicker and more effective immune response.

In summary, adjuvants play a crucial role in vaccinations by enhancing and prolonging the body's immune response to the antigen. They do this by stimulating the innate immune response, which in turn enhances the adaptive immune response.