How is a subunit vaccine developed?

A subunit vaccine is developed by isolating specific pieces of the pathogen that are capable of eliciting an immune response. This targeted approach focuses on the antigenic components of the pathogen that are necessary to stimulate the immune system effectively without using the entire microorganism.

The process involves inserting the gene encoding for the desired antigen onto a plasmid, which is then introduced into a suitable host organism—commonly bacteria or yeast. This host organism uses the plasmid to produce the protein that mimics the pathogen's antigen. The immune system can then recognize this protein, leading to the production of antibodies and memory cells that provide future protection against the actual pathogen if encountered.

This method has several advantages: it minimizes the risk associated with using live pathogens, reduces side effects, and allows for the production of safer vaccines since only the harmless components are used to stimulate the immune response. In contrast, utilizing the entire pathogen, live weakened pathogens, or toxins from the pathogen poses greater risks and is not the characteristic approach for subunit vaccine development.