Final answer:
A DNA vaccine contains a DNA fragment that encodes for a biomolecule of the microorganism serving as an antigen, such as the hepatitis B vaccine, which uses yeast to produce the antigenic hepatitis B surface protein. These vaccines use recombinant DNA to stimulate the immune response without using live pathogens, and advances in rDNA technology have improved their development and efficacy.
Step-by-step explanation:
The vaccine that contains a DNA fragment encoding for a biomolecule of the microorganism, which serves as an antigen, is known as a DNA vaccine. This type of vaccination strategy involves the use of recombinant plasmid technology to introduce genes coding for the antigen into the human body, resulting in cellular uptake, expression of the antigen, and subsequent stimulation of both humoral and cellular immunity. One well-known example of a vaccine created using DNA fragment technology is the vaccine for hepatitis B, where a gene encoding the hepatitis B surface protein is inserted into yeast cells. The yeast then produces this viral protein, which acts as an antigen to stimulate the immune system, without the need for the presence of the actual virus.
Sub-unit vaccines, such as the hepatitis B vaccine, utilize genetic engineering to generate a single antigenic molecule from the pathogen. The DNA fragment technology applied in creating these vaccines is a remarkable shift from traditional methods that use whole organisms. These vaccines can be highly specific, safe, and cost-effective, benefiting from advances in rDNA technology and knowledge of antigens and genomes of causative agents in viral diseases.
Although the production of DNA vaccines remains a meticulous process entailing the generation and purification of the antigenic proteins, advances in rDNA and cloning technologies have paved the way for more efficient vaccine development. For instance, recombinant vaccines can include antigenic epitopes from different strains mixed into a plasmid vector to create a vaccine capable of inducing immunity against multiple strains of a virus.