Qdenga TAK-003 Dengue Vaccine — Tetravalent, Seronegative, Transmission Blocking | UPSC Health Science MCQ 2026
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Question (English)
Consider the following statements regarding India's first approved dengue vaccine, Qdenga (TAK-003):
Statement I: Qdenga is a tetravalent dengue vaccine that does not require prior dengue infection testing before administration, unlike some earlier dengue vaccines.
Statement II: Qdenga is a transmission-blocking vaccine, meaning it prevents the Aedes mosquito from transmitting the dengue virus after biting a vaccinated individual.
Which one of the following is correct in respect of the above statements?
- Statement I is correct but Statement II is not correct ✓ Correct
- Both Statement I and Statement II are correct and Statement II explains Statement I
- Both Statement I and Statement II are correct but Statement II does not explain Statement I
- Statement I is not correct but Statement II is correct
Correct Answer: Statement I is correct but Statement II is not correct
Statement I is correct: Qdenga (TAK-003) does not require prior dengue infection testing, making its rollout significantly easier compared to Sanofi's Dengvaxia vaccine. Statement II is incorrect: Qdenga is a disease-modifying vaccine, NOT a transmission-blocking vaccine. It reduces clinical severity in those who get infected but does not prevent infection itself or stop mosquitoes from transmitting the virus.
Understanding Qdenga (TAK-003)
- Type: Tetravalent dengue vaccine (targets all 4 serotypes: DENV-1, DENV-2, DENV-3, DENV-4).
- Developer: Takeda Pharmaceuticals (Japan).
- Approval in India: Cleared by the Subject Expert Committee (SEC) under the Drugs Controller General of India (DCGI) for persons aged 4 to 60 years.
- Trial scale: Tested on 28,000+ participants; approved in 40+ countries.
Disease-Modifying vs Transmission-Blocking Vaccines
- Disease-modifying vaccine (Qdenga): Reduces severity of illness in vaccinated individuals who get infected. Does NOT prevent the virus from infecting the person or from being transmitted further.
- Transmission-blocking vaccine: Would prevent the mosquito from picking up or transmitting the pathogen from/to a vaccinated person. Qdenga is not in this category.
Key Limitations of Qdenga in India
- Strong efficacy against DENV-2 but lower efficacy against DENV-3 and DENV-4 especially in seronegative (never previously infected) individuals.
- India's shift towards rising DENV-3 (20–30% of cases) may reduce overall population-level impact.
- Cost: Full two-dose course estimated at ₹6,000–₹12,000.
India's Homegrown Alternative
DengiAll (by Panacea Biotec & ICMR) targets balanced protection across all 4 serotypes; potentially available by 2027.
