UPSC Prelims Practice Questions — On guard

Q1. In antibody-dependent enhancement (ADE) of dengue, the sub-neutralising antibody–virus immune complexes gain entry into host cells principally through which class of cell-surface receptors?

  • A. Fc-gamma (Fcγ) receptors on monocytes and macrophages
  • B. Toll-like receptors on circulating T lymphocytes
  • C. ACE-2 receptors on respiratory epithelial cells
  • D. Complement CR1 receptors on mature erythrocytes

Q2. In the context of dengue, 'antibody-dependent enhancement' most precisely refers to which one of the following?

  • A. Sub-neutralising antibodies from a prior heterotypic infection facilitating viral entry into Fc-receptor cells, worsening a subsequent infection by a different serotype
  • B. The gradual strengthening of protective antibody titres with each successive dengue infection until lifelong immunity to all serotypes is achieved
  • C. Booster vaccine doses raising antibody levels so that a single serotype infection confers durable cross-protection against the other three
  • D. Maternal antibodies transferred across the placenta enhancing an infant's own immune response to its first dengue exposure

Q3. With reference to Qdenga and its predecessor Dengvaxia, consider the following statements: 1. Qdenga is a live-attenuated tetravalent vaccine, whereas Dengvaxia is a chimeric yellow-fever-based tetravalent vaccine. 2. Qdenga requires documented prior dengue infection before administration, a screening requirement that Dengvaxia does not impose. 3. Both vaccines are designed to protect against all four dengue virus serotypes. Which of the statements given above is/are correct?

  1. Qdenga is a live-attenuated tetravalent vaccine, whereas Dengvaxia is a chimeric yellow-fever-based tetravalent vaccine.
  2. Qdenga requires documented prior dengue infection before administration, a screening requirement that Dengvaxia does not impose.
  3. Both vaccines are designed to protect against all four dengue virus serotypes.
  • A. 1 and 2 only
  • B. 1 and 3 only
  • C. 2 and 3 only
  • D. 1, 2 and 3

Q4. Regarding the recent approval of Qdenga in India, consider the following: 1. Marketing authorisation was granted by the CDSCO through the Drug Controller General of India. 2. The vaccine has been approved for use in the age group 4 to 60 years. 3. It is administered as a single-dose regimen. 4. The vaccine is imported into India, being manufactured by Takeda in Germany. Which of the above is/are correctly identified?

  1. Marketing authorisation was granted by the CDSCO through the Drug Controller General of India.
  2. The vaccine has been approved for use in the age group 4 to 60 years.
  3. It is administered as a single-dose regimen.
  4. The vaccine is imported into India, being manufactured by Takeda in Germany.
  • A. 1, 2 and 4
  • B. 1, 3 and 4
  • C. 2 and 3 only
  • D. 1 and 4 only

Q5. After the seronegative-risk data emerged in 2017, which body issued the global recommendation that Dengvaxia be used only in persons with confirmed prior dengue infection?

  • A. The World Health Organization
  • B. The United States Centers for Disease Control and Prevention
  • C. The European Medicines Agency
  • D. Sanofi Pasteur's internal safety board

Q6. With reference to the Dengvaxia episode, consider the following: 1. Dengvaxia was developed by Sanofi Pasteur. 2. In November 2017, the manufacturer announced an increased risk of severe dengue in seronegative recipients. 3. Around 800,000 children in the Philippines had been vaccinated by the time the risk was disclosed. 4. Dengvaxia is a live-attenuated vaccine constructed on a DENV-1 genetic backbone. Which of the above is/are correctly identified?

  1. Dengvaxia was developed by Sanofi Pasteur.
  2. In November 2017, the manufacturer announced an increased risk of severe dengue in seronegative recipients.
  3. Around 800,000 children in the Philippines had been vaccinated by the time the risk was disclosed.
  4. Dengvaxia is a live-attenuated vaccine constructed on a DENV-1 genetic backbone.
  • A. 1, 2 and 3
  • B. 1, 3 and 4
  • C. 2 and 4 only
  • D. 1, 2 and 4

Q7. The 'WHO prequalification' of a vaccine most accurately signifies which one of the following?

  • A. An assurance that the vaccine meets WHO standards of quality, safety and efficacy so that UN agencies such as UNICEF may procure it
  • B. A binding marketing authorisation that makes the vaccine legally saleable across all WHO member states
  • C. A certification issued only after WHO has itself conducted the pivotal clinical trials of the vaccine
  • D. An endorsement that removes the requirement for any separate national regulatory approval of the vaccine

Q8. Consider the following pairings of body and function: 1. CDSCO — India's central regulator for drugs and vaccines under the Drugs and Cosmetics Act, 1940. 2. Drug Controller General of India — the head of CDSCO who grants marketing authorisation for new drugs. 3. WHO Prequalification — enables procurement of vaccines by UN agencies such as UNICEF. 4. National Vector Borne Disease Control Programme — the statutory authority that grants clinical-trial approvals for vaccines in India. Which of the above pairings is/are NOT correctly matched?

  1. CDSCO — India's central regulator for drugs and vaccines under the Drugs and Cosmetics Act, 1940.
  2. Drug Controller General of India — the head of CDSCO who grants marketing authorisation for new drugs.
  3. WHO Prequalification — enables procurement of vaccines by UN agencies such as UNICEF.
  4. National Vector Borne Disease Control Programme — the statutory authority that grants clinical-trial approvals for vaccines in India.
  • A. 4 only
  • B. 1 and 4
  • C. 3 and 4
  • D. 2 only

Q9. Which one of the following is the nodal agency of the Government of India for the control of dengue and other vector-borne diseases?

  • A. National Center for Vector Borne Diseases Control under the Directorate General of Health Services
  • B. National Centre for Disease Control under the Ministry of Health and Family Welfare
  • C. ICMR-National Institute of Malaria Research under the Department of Health Research
  • D. Central Pollution Control Board under the Ministry of Environment, Forest and Climate Change

Q10. With reference to the mosquito vectors of dengue in India, consider the following statements: 1. Aedes aegypti is the primary dengue vector and breeds mainly in man-made water containers. 2. Aedes mosquitoes are typically day-biting and are small, black with white stripes. 3. Aedes albopictus, unlike Aedes aegypti, cannot transmit dengue virus and acts only as a nuisance mosquito. Which of the statements given above is/are correct?

  1. Aedes aegypti is the primary dengue vector and breeds mainly in man-made water containers.
  2. Aedes mosquitoes are typically day-biting and are small, black with white stripes.
  3. Aedes albopictus, unlike Aedes aegypti, cannot transmit dengue virus and acts only as a nuisance mosquito.
  • A. 1 and 2 only
  • B. 2 and 3 only
  • C. 1 and 3 only
  • D. 1, 2 and 3

Q11. Under the schedule approved in India, the two doses of Qdenga are to be administered how many months apart?

  • A. 3 months
  • B. 1 month
  • C. 6 months
  • D. 12 months

Q12. With reference to the global dengue vaccine landscape, which one of the following statements is correct?

  • A. Dengvaxia was the world's first licensed dengue vaccine
  • B. Qdenga is the only dengue vaccine ever to have received WHO prequalification
  • C. Qdenga provides complete protection against all four serotypes even in dengue-naïve persons
  • D. Dengvaxia can be safely administered to all individuals irrespective of their serostatus