Jenner - use of cowpox and vaccination B. Tables 18. Whole agent - either attenuated or inactivated viruses or bacteria 2. Subunit vaccines employ only a part e.g. Pili, capsular antigen. The vaccine for Hepatitis B is a subunit vaccine - viral coat protein produced in geneticially engineered yeast. Recently, a subunit vaccine for Bordetella pertussis has been developed.
Some subunit vaccines are products of genetic engineering and are called recombinant vaccines.
Acellular vaccines are made from disrupting bacterial cells and using only the antigenic fragments that are released from the cells. Toxoids, or inactivated toxins 4. Conjugated vaccines made by combining poorly immunogenic materials such as polycaccharides with more immunogenic proteins 5. Nucleic acid vaccines are still in the experimental stages. The idea is that injected DNA will direct the synthesis of antigenic proteins which are then presented to T cells along with the host's own MHC molecules to induce a good cell mediated response.