Qdenga: a step forward against dengue, but not a silver bullet, Pg9

Key Highlights:

• Qdenga (TAK-003), a tetravalent dengue vaccine developed by Takeda, has been cleared by the Drugs Controller General of India (DCGI) for individuals aged 4 to 60 years.
• The vaccine has been approved in over 40 countries and evaluated in trials involving over 28,000 participants.
• TAK-003 offers protection against severe dengue and hospitalization, but its effectiveness varies across the four dengue serotypes (DENV-1 to DENV-4).
• The vaccine requires two doses administered three months apart, with an expected cost of ₹6,000-12,000 for the full course.

Detailed Insights:

• Dengue control in India has primarily relied on vector control, which has had limited success in preventing outbreaks.
• TAK-003 does not require pre-vaccination screening, simplifying its use, and aims to reduce the severity of illness rather than prevent infection altogether.
• While effective against DENV-2 and reasonably effective against DENV-1, TAK-003 shows lower effectiveness against DENV-3 and DENV-4, particularly in those not previously infected.
• Surveillance data indicates that all four dengue serotypes co-circulate in India, with DENV-2 predominant in many regions but DENV-3 contributing a substantial and increasing proportion of cases.
• India's dengue vaccine pipeline includes 'DengiAll', developed by Panacea Biotec in collaboration with the Indian Council of Medical Research, currently undergoing phase III clinical trials.
• Post-marketing studies are mandated to understand the vaccine's performance in real-world conditions across different regions and serotype patterns.
• Policymakers need to balance the urgency of reducing severe dengue cases with the flexibility to adopt better vaccines as evidence evolves.

Key Concepts Involved:

• Dengue Serotypes (DENV-1 to DENV-4): Distinct variations of the dengue virus, each requiring specific immunity.
• Vector Control: Methods to limit the spread of disease by managing or eliminating the vector population, such as mosquitoes.
• Post-Marketing Surveillance: Monitoring the safety and effectiveness of a pharmaceutical drug or device after it has been released on the market.