Context
Recently, the Subject Expert Committee (SEC) of the Central Drugs Standard Control Organisation (CDSCO) has recommended the approval for the import and marketing of the Japanese dengue vaccine, Qdenga, in India for the age group of 4 to 60 years. This development marks a significant step as India currently has no licensed dengue vaccine in its public immunization program despite a high disease burden.
1. Basic Profile
- Manufacturer: Developed by Takeda Pharmaceuticals, a Japanese biopharmaceutical giant.
- Type of Vaccine: It is a Live-Attenuated Vaccine, meaning it uses a weakened form of the virus that causes the disease.
- Composition: It is a tetravalent vaccine, designed to protect against all four serotypes of the dengue virus: DENV-1, DENV-2, DENV-3, and DENV-4.
- Backbone: The vaccine is built on a live-attenuated dengue serotype 2 (DENV-2) virus, which provides the genetic “backbone” for all four components.
2. Administration and Efficacy
- Dosage: It is a two-dose vaccine administered subcutaneously, with a gap of three months between doses.
- Serostatus Independence: Unlike its predecessor Dengvaxia, Qdenga can be administered to individuals regardless of previous dengue exposure (seropositive or seronegative). This eliminates the need for pre-vaccination screening.
- Global Status: It was prequalified by the World Health Organization (WHO) in May 2024 and is already approved in over 40 countries, including parts of the European Union, Brazil, and Indonesia.
3. Comparison: Qdenga vs. Dengvaxia
| Feature | Qdenga (TAK-003) | Dengvaxia (CYD-TDV) |
| Manufacturer | Takeda (Japan) | Sanofi Pasteur (France) |
| Platform | DENV-2 Backbone | Yellow Fever Virus Backbone |
| Pre-testing | Not required | Required (Only for seropositive) |
| Doses | 2 Doses (3 months apart) | 3 Doses (6 months apart) |
| Risk | Lower risk of severe dengue in naive | High risk of severe dengue in naive |
4. Indian Context and Manufacturing
- CDSCO Approval: The Subject Expert Committee has recommended it for the 4–60 age group in India.
- Local Partnership: Takeda has entered into a partnership with Hyderabad-based Biological E to manufacture the vaccine, aiming to produce 100 million doses annually to ensure supply for India and other endemic regions.
- Indigenous Candidates: While Qdenga is an imported technology, India is also developing indigenous candidates like DengiAll (by Panacea Biotec and ICMR), which is currently in Phase III trials.
- Current Affairs: The WHO prequalification and India’s recent regulatory nod make it a high-probability topic for Prelims 2026.
Q. With reference to the 'Qdenga' vaccine, recently seen in the news, consider the following statements:
Statement-I: It is a live-attenuated tetravalent vaccine developed to provide protection against all four serotypes of the dengue virus.
Statement-II: Unlike the previously available Dengvaxia, Qdenga requires mandatory pre-vaccination screening to ensure it is only given to people who have had a prior dengue infection.
Which one of the following is correct in respect of the above statements?
(a) Both Statement-I and Statement-II are correct and Statement-II is the correct explanation for Statement-I.
(b) Both Statement-I and Statement-II are correct and Statement-II is not the correct explanation for Statement-I.
(c) Statement-I is correct but Statement-II is incorrect.
(d) Statement-I is incorrect but Statement-II is correct.
Answer: (c)
Solution:
• STATEMENT I IS CORRECT: Qdenga (TAK-003) is indeed a live-attenuated vaccine that uses a DENV-2 backbone to provide tetravalent protection against all four dengue serotypes (DENV-1 to 4).
• STATEMENT II IS INCORRECT: This is a false statement because Qdenga's primary advantage is that it is serostatus-independent. It can be administered to individuals regardless of whether they have been previously infected with dengue or not, thus not requiring mandatory pre-vaccination screening. This distinguishes it from Dengvaxia, which can increase the risk of severe dengue in "seronegative" (never-infected) individuals.
