The researchers at India’s National Centre for Biological Sciences, collaborating with nine other institutions globally, have made a significant breakthrough in the prevention of dengue fever. This team of scientists has engineered India’s first DNA vaccine candidate for dengue fever. During its initial trials on mice, this potential vaccine exhibited promising results by provoking a robust immune response and enhancing survival rates following exposure to the disease.
About DNA Vaccines
What are DNA vaccines? They are a genre of vaccine that employs a small segment of DNA coding for a specific antigen – a molecule that actuates an immune response – originating from a pathogen like a virus or bacterium. This DNA is directly infused into the body’s cells, where it instructs them to create the antigen. Consequently, the immune system identifies this antigen as alien, triggering an immune response against it, thus building immunity to the pathogen. These vaccines mark the third generation of vaccination innovation. An example is ZyCoV-D, which is both the world’s first and India’s domestically developed DNA-based vaccine for COVID-19.
Understanding Dengue
Dengue is a tropical disease transmitted by mosquitoes and caused by the dengue virus (Genus Flavivirus). Several species within the Aedes genus, primarily Aedes aegypti, spread the virus. Along with dengue, this mosquito species also transmits chikungunya and Zika infection. Four closely related yet distinct serotypes (groups within a species sharing a particular characteristic) of this virus can cause Dengue – DEN-1, DEN-2, DEN-3, and DEN-4. Symptoms of Dengue include sudden high fever, severe headaches, eye pain, and severe bone, joint, and muscle pain.
Dengue Vaccines and their Development Challenges
In 2019, the US Food & Drug Administration approved the Dengvaxia or the dengue vaccine CYD-TDV – the first-ever dengue vaccine to receive a regulatory endorsement in the US. Dengvaxia is essentially a live, attenuated dengue virus intended for administration in individuals aged 9 to 16 years with laboratory-confirmed past dengue infection and residing in endemic regions.
Designing an effective dengue vaccine poses considerable challenges because dengue can be caused by any of the four closely associated virus serotypes, each interacting differently with human blood antibodies. For instance, after infection with DEN-1, a person gains lifetime protection against it, but not the other three serotypes. Hence, an ideal vaccine should target all serotypes. Furthermore, while vaccines generally stimulate the generation of antibodies that inhibit viruses from binding to cells during later exposure, with dengue, these antibodies rather assist the virus in replication, thereby exacerbating the disease.
UPSC Civil Services Examination: Past Questions
For the 2022 UPSC Civil Services Examination, here are some past questions related to this topic. For the prelims, consider the following statements about COVID-19 vaccine manufacturing:
– The Serum Institute of India produced the Covishield vaccine using an mRNA platform.
– Sputnik V vaccine uses a vector-based platform.
– COVAXIN is an inactivated pathogen-based vaccine.
Which ones are correct? The answer is (b) Statements 2 and 3 only.
In the mains, here’s a question from 2022: What forms the basic principle for vaccine development? How do vaccines operate? What strategies did Indian vaccine manufacturers apply in producing COVID-19 vaccines?
Source
The facts and details presented in this article were obtained primarily from Down To Earth or DTE.