Recombinant DNA technology has fundamentally changed vaccine development by allowing for the production of "subunit" vaccines, which contain only a specific part of a pathogen (like a surface protein) rather than the whole virus or bacteria. This eliminates the risk of the vaccine causing the disease it is intended to prevent. The Hepatitis B vaccine was the first successful recombinant vaccine, produced by expressing the Hepatitis B surface antigen (HBsAg) in yeast cells.

In addition to subunit vaccines, rDNA technology is at the heart of viral vector vaccines. In this approach, a harmless virus (like an adenovirus) is genetically modified to carry the genetic code for a specific antigen from a different pathogen. For a breakdown of the viral vector systems and the genetic stability testing required for these products, the Recombinant DNA Technology Market documentation offers a technical overview. This technology provides a versatile platform that can be rapidly adapted to respond to emerging infectious diseases.

The engineering of viral vectors is also a cornerstone of gene therapy, where recombinant DNA is used to deliver functional genes to patients with genetic disorders. By replacing a "broken" gene with a healthy one, these therapies aim to provide long-term or even permanent cures. As our ability to engineer these delivery vehicles improves, the scope of rDNA-based vaccines and therapies will continue to expand, offering new hope for the treatment of both infectious and hereditary diseases.