25 Jul On Guard: Making the Dengue Vaccine Affordable for Those at Greatest Risk

Why in News?

The Central Drugs Standard Control Organisation (CDSCO) has approved Qdenga, India’s first licensed dengue vaccine, marking a significant step in combating the country’s growing dengue burden. However, experts stress that affordability, targeted deployment, and continued vector control will determine its public health impact.

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Context

• India has experienced one of its worst dengue outbreaks in recent years.
• Qdenga, developed by Takeda (Japan), is now approved in India after being licensed in over 40 countries and receiving WHO prequalification.
• Unlike the earlier dengue vaccine Dengvaxia, Qdenga does not require prior screening for previous dengue infection, simplifying its administration.

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About Dengue

Causative Agent

• Dengue is caused by the Dengue virus (DENV), transmitted through the Aedes aegypti mosquito.

Four Serotypes

• DENV-1
• DENV-2
• DENV-3
• DENV-4

Infection with one serotype provides lifelong immunity only against that serotype, while subsequent infection by another serotype can increase the risk of severe dengue due to Antibody-Dependent Enhancement (ADE).

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About Qdenga Vaccine

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Why is Qdenga Significant?

1. First Dengue Vaccine in India

• Marks India’s first licensed dengue vaccine.
• Expands preventive options beyond mosquito control.

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2. Simpler Administration

Unlike Dengvaxia:

• No need to determine prior dengue infection.
• Easier inclusion in vaccination programmes.

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3. Public Health Benefit

Can reduce:

• Severe dengue cases.
• Hospitalisation.
• Disease burden in endemic regions.

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Challenges and Concerns

1. Uneven Protection Across Serotypes

Clinical evidence indicates:

• Highest protection against DENV-2.
• Good protection against DENV-1.
• Uncertain effectiveness against DENV-3 and DENV-4, especially in people without previous dengue infection.

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2. Rising DENV-3 Prevalence

• DENV-3 infections are increasing in India.
• If DENV-3 dominates future outbreaks, vaccine effectiveness may be lower than expected.

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3. Two-Dose Schedule

• Requires two doses over three months.
• Ensuring completion among:
  • Migrant workers
  • Urban poor
  • Mobile populations
    may be challenging.

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4. Affordability

• Takeda follows a tiered pricing strategy globally.
• The vaccine may remain expensive for vulnerable populations unless government negotiates lower prices.
• High cost could reduce vaccine uptake among high-risk groups.

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5. Not a Substitute for Vector Control

Vaccination alone cannot eliminate dengue.
Continued emphasis is needed on:

• Source reduction.
• Mosquito breeding control.
• Public awareness.
• Surveillance.

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Dengvaxia vs Qdenga

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Policy Recommendations

1. Ensure Affordable Pricing

• Government should negotiate lower procurement prices.
• Consider inclusion under public immunisation programmes for high-risk groups.

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2. Target High-Risk Areas

Priority should be given to:

• Urban slums.
• High-incidence districts.
• Regions with repeated outbreaks.

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3. Strengthen Disease Surveillance

• Monitor circulating dengue serotypes.
• Track vaccine effectiveness against different variants.

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4. Improve Vaccination Coverage

• Ensure completion of the two-dose schedule.
• Use digital tracking and follow-up mechanisms.

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5. Continue Integrated Vector Management

Vaccination should complement:

• Mosquito control.
• Community participation.
• Early diagnosis.
• Public health awareness.

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Way Forward

India’s approval of Qdenga is an important milestone in dengue prevention. However, its success depends on affordable pricing, scientific deployment based on epidemiological evidence, completion of the two-dose schedule, and continued investment in surveillance and vector control.

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Conclusion

Qdenga offers a promising new tool against dengue but is not a standalone solution. To maximise public health benefits, India must ensure equitable access, monitor vaccine performance against different serotypes, and integrate vaccination with comprehensive dengue control strategies.

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UPSC Prelims Practice Question

Q. With reference to the Qdenga vaccine, consider the following statements:

1. It is India’s first licensed dengue vaccine approved by the CDSCO.
2. Prior screening for previous dengue infection is mandatory before administering Qdenga.
3. It requires two doses administered three months apart.

Which of the statements given above is/are correct?

(a) 1 and 3 only
(b) 2 only
(c) 1, 2 and 3
(d) 3 only

Answer: (a) 1 and 3 only

Explanation

• Statement 1 is Correct: Qdenga is the first dengue vaccine approved by the CDSCO for use in India.
• Statement 2 is Incorrect: Unlike Dengvaxia, Qdenga does not require prior screening for previous dengue infection, making it easier to deploy in public health programmes.
• Statement 3 is Correct: Qdenga is administered in a two-dose schedule, with the second dose given three months after the first.

Hence, the correct answer is (a) 1 and 3 only.