Context
The World Health Organisation (WHO) recently announced the prequalification of a second vaccine for dengue, called TAK-003, made by a Japanese drug maker.
Live Attenuated Vaccines
Live vaccines are derived from “wild” viruses or bacteria which have been attenuated (weakened) in a laboratory, usually by repeated culturing. For example, the measles virus used as a vaccine today was isolated from a child with measles disease in 1954. |
WHO Prequalifies new Dengue Vaccine
- WHO has prequalified a second vaccine for dengue, known as TAK-003, made by the Japanese drug maker Takeda Pharmaceuticals.
- Nature: It is a live-attenuated vaccine containing weakened versions of the four serotypes of the virus that cause dengue. Thus it helps the body to build immunity against all the four dengue viruses.
- Target Age Group: TAK-003 can be administered to children aged 6 to 16 years, with a high dengue burden and transmission intensity.
- Dosage: The vaccine should be administered in a 2-dose schedule with a 3-month interval between doses, as per the WHO.
- Global Approval Status: The UK, Brazil, Argentina, Indonesia and Thailand have also approved TAK-OO3.
- First Vaccine: The WHO had previously prequalified the Dengvaxia CYD-TDV vaccine against dengue, developed by Sanofi Pasteur.
- It was also a live, attenuated dengue virus which has to be administered in people of ages 9 to 16.
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India’s DNA Vaccine Candidate against Dengue
- The Serum Institute of India made major progress in the development of India’s first and only DNA vaccine candidate for dengue fever.
- The Vaccine is under preliminary trial stage and has given promising results.
DNA Vaccines:
- DNA Vaccines puts a specific DNA sequence that codes for an antigen into an organism’s cells to trigger an immune response.
- Dengue is caused by four closely related viruses (DEN-1, DEN-2, DEN-3, and DEN-4), known as serotypes.
- Infection with one serotype provides lifelong protection against it but not the others, necessitating a vaccine that targets all four.
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What is Dengue?
Dengue is a mosquito-borne tropical disease caused by the dengue virus (Genus Flavivirus), transmitted by several species of mosquito within the genus Aedes, principally Aedes aegypti.
- Causative Agent: It is a tropical disease caused by the dengue virus (Genus Flavivirus). It is spread through the bite of infected Aedes species (Ae. aegypti or Ae. albopictus) mosquito.
- These mosquitoes also spread Chikungunya, Yellow fever and Zika viruses
- Serotypes of Dengue: There are 4 distinct, but closely related, serotypes (separate groups within a species of microorganisms that all share a similar characteristic) of the virus that cause dengue (DEN-1, DEN-2, DEN-3 and DEN-4).
- Vulnerability: It is estimated that there are over 100 to 400 million cases of dengue worldwide each year and 3.8 billion people living in dengue-endemic countries, most of which are in Asia, Africa, and the Americas.
- Symptoms: High fever, headache, body aches, nausea and rash. Severe dengue can cause belly pain, vomiting, bleeding from the nose or gums, and extreme fatigue
- Control and Prevention: Recently, the World Mosquito Program used mosquitoes infected with Wolbachia bacteria to successfully control dengue in Indonesia.
Significance of Prequalification Status
- Assurance of Quality, Safety, and Efficacy: WHO prequalification confirms that the vaccine meets rigorous international standards for quality, safety, and efficacy.
- Global Usage and Acceptance: This status allows the vaccine to be used globally, especially beneficial for low- and middle-income countries where such rigorous evaluation might not be feasible locally.
- Facilitates Wider Distribution: Prequalification enables the vaccine’s inclusion in procurement processes by UN agencies and other global health organizations, thus promoting wider distribution.
- Support for Public Health Programs: The approval aids in the integration of the vaccine into public health programs, enhancing disease prevention strategies worldwide.
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