DNA vaccine: Methods and mechanisms

Infectious diseases are the biggest cause of mortality and morbidity in humans, especially in poor and developing countries. For many years, no new vaccine has been developed, which indicates the limitations of the development of common vaccines, including destruction and inactivation of the vaccine, weakened vaccines toxoids known as first-generation vaccines. Types of vaccines including: (1) First-generation vaccines, (2) second-generation vaccines or recombinant vaccines, (3) third-generation vaccines (gene vaccine). The study on DNA vaccines first began in the 1990s, when the plasmid DNA is injected into the skin or muscle was reported to induce antibody responses to antigens. Since DNA vaccines are easily designed and manufactured, they are easier to preserve them, and they are inexpensive, as one of the most desirable types of vaccine. However, more clinical trials are needed to prove the immune responses that immune to DNA vaccine in humans. Information on the vaccination method, adjuvant and the genetic structure of the vaccine is still not complete.