Vaccines & Vaccination

DNA Vaccines

DNA vaccination is a technique for protecting an animal against disease by injecting it with genetically engineered DNA so cells directly produce an antigen, resulting in a protective immunological response.

Vaccination consists of stimulating the immune system with an infectious agent, or components of an infectious agent, modified in such a manner that no harm or disease is caused, but ensuring that when the host is confronted with that infectious agent, the immune system can adequately neutralize it before it causes any ill effect. For over a hundred years vaccination has been effected by one of two approaches: either introducing specific antigens against which the immune system reacts directly; or introducing live attenuated infectious agents that replicate within the host without causing disease synthesize the antigens that subsequently prime the immune system.

The field of DNA vaccination is developing rapidly. Vaccines currently being developed use not only DNA, but also include adjuncts that assist DNA to enter cells, target it towards specific cells, or that may act as adjuvants in stimulating or directing the immune response. Ultimately, the distinction between a sophisticated DNA vaccine and a simple viral vector may not be clear. Many aspects of the immune response generated by DNA vaccines are not understood. However, this has not impeded significant progress towards the use of this type of vaccine in humans, and clinical trials have begun.