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Source: The post is based on the article “Decoding dengue: India’s first prospective DNA vaccine against disease is promising; but challenges lie ahead” published in Down To Earth on 4th March 2023.
What is the News?
In a significant development in DNA vaccination research, India’s first and only DNA vaccine candidate for dengue has shown promising results.
What is Dengue?
What is DNA Vaccine?
DNA vaccines are third-generation vaccines. They are a type of vaccine that uses a small piece of DNA that codes for a specific antigen (a molecule that triggers an immune response) from a pathogen, such as a virus or bacterium, to stimulate an immune response.
The DNA is injected directly into the body’s cells, where it instructs the cells to produce the antigen.
The immune system then recognizes the antigen as foreign and mounts an immune response against it, which helps to develop immunity to the pathogen.
The ZyCoV-D is the world’s first and India’s indigenously developed DNA-based vaccine for COVID-19.
What are the challenges in developing a DNA Vaccine against dengue?
Firstly, developing an effective vaccine against dengue is tricky because it is caused by four closely related virus serotypes. Each one interacts differently with antibodies in human blood. A person infected with DEN-1 is then protected against it for life, but not against the other three serotypes. An ideal vaccine must target all serotypes.
Secondly, vaccines trigger the production of antibodies that prevent the virus from binding to cells at later exposure. But with dengue, antibodies help the virus replicate and cause severe disease.