Biotechnology and Bioinformatics (1+1)

4.3.11. Advantages of DNA vaccines

DNA vaccines overcome almost all the drawbacks of all other form of vaccines. Major advantage of DNA vaccines over recombinant protein vaccine lies in its ability to induce production of native form of protein with appropriate post-translational modifications. This has been shown in the case of DNA immunization of rainbow trout. Upon injection of plasmids carrying VHSV G protein gene, the expressed G protein is recognized by specific monoclonal antibodies.

Additionally, DNA vaccines are able to induce long lasting immune response and are economical and safe. Practical application of DNA vaccine in fish does not seem to be encouraging because most of the important fish pathogens, especially the viruses those affect fish at a very young age. This makes it difficult for one to administer vaccine to small fish through injection route, which is so far the only method of introducing the DNA vaccines. However, the present methods of administration of DNA vaccine, such as use of injection machines are still useful for immunizing broodstocks of fairly large fish so as to ensure that immunity is passively transferred from mother to offspring as this being demonstrated in controlling Ich. Therefore, it is difficult to use DNA vaccines for individual fish on a large scale in intensive aquaculture unless one can introduce DNA vaccine to fish orally or through gill filaments via aquatic medium.