Dna Vaccination Advantages

Vaccines represent one of the great achievements in public health. A turning point in the war against pathogenic infection occurred over 200 years ago when Edward Jenner used cowpox to elicit protective immune responses against a devastating outbreak of smallpox. Since then, the use of safe and effective vaccines to prevent infection has become a fundamental aspect of modern medicine. While many vaccination campaigns have been successful, the constant emergence, and re-emergence, of pathogens challenges scientists to develop new vaccination technologies with improved safety and efficacy. One such approach that has increasingly come to the forefront is DNA vaccination. DNA vaccines are bacterial plasmids that encode the polypeptide sequence
DNA vaccine design generally requires only one-step cloning into the plasmid vector, reducing both the cost of production and production time. Plasmid DNA is also extremely stable at room temperature, avoiding the need for a cold chain during transportation. Vaccination with DNA plasmid removes the necessity of purifying proteins from infectious pathogens, improving safety. Furthermore, DNA vaccination has an excellent safety profile in the clinic, with the most common side effect being mild inflammation at the injection site. Importantly, DNA vaccines provide a safe, non-live vaccine approach to inducing balanced immune responses, as the in vivo production of antigen allows for presentation on both class I and class II major histocompatibility complex (MHC) molecules. This results in the elicitation of both antigen specific antibodies [3] and cytotoxic T lymphocyte responses (CTL) [4], something that remains elusive in most non-live vaccines. DNA vaccines have shown a particular knack for generating T helper populations, which are critical for the induction of high quality antigen-specific B cell
Therefore it is not surprising that the method and route of vaccination has a significant effect on DNA vaccine efficacy. While a wide range of DNA vaccine delivery approaches have been employed, they can generally be divided into two groups, chemical delivery and physical delivery. Physical delivery approaches utilize a particular physical force (such as air pressure or electrical pulse) to deliver the DNA plasmids into targeted tissues or cells. The most common physical methods are electroporation [10-14] and gas-powered particle bombardment with a ballistic gene gun [7, 15-17]. Several needle-free injection systems have also been investigated. These so-called pneumatic or jet injectors have shown promise in both animal and human clinical trials [18-21], and function by injecting a high-pressure, narrow stream of injection liquid into the epidermis of patients. In contrast, chemical delivery approaches use biopharmaceuticals to increase DNA vaccine transfection efficiency. As physical delivery systems have been covered in depth in several other places, this review will focus on recent advancements in chemical