How DNA Vaccines Differ from Recombinant DNA Vaccines
The immunogenic protein associated with a recombinant DNA vaccine is made in the laboratory and injected into the vaccine recipient, while the immunogenic protein associated with a DNA vaccine is generated by the cells of the host. Recombinant DNA vaccines are based on the expression of biological constructs encoding proteins from specific viral pathogens, and are not themselves made of DNA. Instead, they are made of protein or glycoprotein subunits synthesized in the laboratory using recombinant DNA technology.
For example, the HBV vaccine was originally made by extracting and purifying the surface antigen (envelope protein) from serum of individuals exposed to HBV virus. This technique was an advance in vaccine manufacture because a purified single protein is less likely to have major side effects -- but this method did not allay fears that an improperly made batch of vaccine might be infectious. Now HBV vaccines are made with recombinant DNA technology. The gene for the HBV envelope protein is placed into yeast or bacteria which make all the envelope protein the manufacturer could desire without any possible risk of HBV infection to the recipient, because neither the virus nor the entire viral genome was ever present in the manufacture process.
Cite this: The Emerging Role of DNA Vaccines - Medscape - Jul 01, 1998.