"India approves first dengue vaccine Qdenga amid affordability and coverage concerns"
Antibody-Dependent Enhancement (ADE)
pre-existing antibodies from one dengue serotype amplify replication of a different serotype, worsening disease severity.
Qdenga (TAK-003)
live attenuated tetravalent dengue vaccine built on a DENV-2 backbone, approved by CDSCO; does not require pre-vaccination serological screening.
Dengue fever is a vector-borne viral illness caused by four antigenically distinct serotypes — DENV-1, DENV-2, DENV-3, and DENV-4 — transmitted primarily by the Aedes aegypti mosquito and secondarily by Aedes albopictus. The WHO classifies dengue as one of the ten threats to global health, estimating 100–400 million infections annually worldwide. No specific antiviral treatment exists; clinical management remains supportive. A critical immunological feature is that infection with one serotype confers lifelong immunity only to that serotype, while a subsequent infection by a different serotype can trigger antibody-dependent enhancement (ADE) — a mechanism by which pre-existing antibodies paradoxically amplify viral replication, increasing the risk of severe dengue haemorrhagic fever or dengue shock syndrome.
In India, vector-borne disease control is governed under the National Vector Borne Disease Control Programme (NVBDCP), administered by the Ministry of Health and Family Welfare. The Aedes mosquito's breeding range has expanded beyond dense urban cores into semi-urban and rural districts, where drainage infrastructure and vector control capacity are weaker. India recorded more than 2.89 lakh dengue cases and 485 deaths in 2023, underscoring the scale of the public health challenge.
The first globally licensed dengue vaccine, Dengvaxia (by Sanofi Pasteur), became a cautionary tale when its rollout in the Philippines caused severe adverse outcomes in seronegative children — those without prior dengue exposure — because ADE was triggered by the vaccine itself acting as a 'first infection'. This controversy prompted stricter global regulatory scrutiny and reinforced the principle that dengue vaccination must account for prior serological status.
Qdenga (TAK-003), developed by Takeda Pharmaceuticals and manufactured in Germany, is a live attenuated tetravalent dengue vaccine built on a DENV-2 backbone into which genes from the other three serotypes are inserted. This chimeric architecture is its key distinguishing feature: unlike Dengvaxia, Qdenga does not require pre-vaccination serological screening, removing a major logistical barrier to deployment in low-resource settings. The Central Drugs Standard Control Organisation (CDSCO) — India's apex drug regulator — granted marketing authorisation in July, making India the 43rd country to approve the vaccine, which has already seen over 24 million doses administered globally and carries WHO prequalification.
The vaccine is administered in two doses, three months apart. Clinical evidence from the TIDES trial (the pivotal Phase III study) shows strong, long-lasting protection against all four serotypes in previously infected (seropositive) individuals. …
In the context of vaccines manufactured to prevent COVID-19 pandemic, consider the following statements:
1.The Serum Institute of India produced COVID-19 vaccine named Covishield using mRNA platform.
2.Sputnik V vaccine is manufactured using vector based platform.
3.COVAXIN is an inactivated pathogen based vaccine.
Which of the statements given above are correct?
With reference to recent developments regarding 'Recombinant Vector Vaccines', consider the following statements:
1.Genetic engineering is applied in the development of these vaccines.
2.Bacteria and viruses are used as vectors.
Which of the statements given above is/are correct?
Which one of the following statements is not correct?
With reference to Qdenga, India's first approved dengue vaccine, consider the following statements:
1.It is built on a DENV-2 backbone into which genes from other serotypes are inserted.
2.It requires mandatory pre-vaccination serological screening before administration.
3.It is contraindicated in children below six years of age.
Which of the statements given above is/are correct?
Which of the following best describes 'Antibody-Dependent Enhancement (ADE)' in the context of dengue fever?
The WHO recommends that countries consider including a dengue vaccine in routine immunisation programmes only when which of the following epidemiological criteria are met?
1.Dengue seroprevalence exceeding 60% by the age of nine years.
2.Mean age of dengue-related hospitalisation below 16 years.
3.Annual dengue case fatality rate exceeding 1% nationally.
Select the correct answer using the codes below:
Consider the following statements about dengue fever in India:
1.Dengue is transmitted primarily by the Aedes albopictus mosquito.
2.The National Vector Borne Disease Control Programme (NVBDCP) is administered by the Ministry of Health and Family Welfare.
3.A person who has recovered from DENV-1 infection has lifelong immunity against all four dengue serotypes.
Which of the statements given above is/are correct?
Assertion (A): Inclusion of Qdenga in India's Universal Immunisation Programme cannot be decided solely on the basis of CDSCO marketing approval.
Reason (R): The WHO recommends UIP inclusion only in regions meeting specific seroprevalence thresholds, and India currently lacks comprehensive district-level dengue seroprevalence data.
Which of the following is correct?
Want the full note, Prelims Facts & MCQ answers?
Create a free account — takes less than a minute.
Create free account