Virus Quiz : Test your knowledge

1. Which of the following best describes a “virulence factor” in the context of viral infections?

1. A host protein that neutralizes the virus.
2. A viral component that enhances the ability to cause disease.
3. A disinfectant used to inactivate viruses in hospitals.
4. A vaccine adjuvant that increases immune response.

2. With reference to “zoonotic spillover” of viruses, which of the following is/are usually required?

1. Sufficient contact between humans and the animal reservoir or intermediate host.
2. A virus capable of binding to human cell receptors.
3. Mandatory presence of an arthropod vector in all cases.

Select the correct answer using the code below:

1. 1 only
2. 1 and 2 only
3. 2 and 3 only
4. 1, 2 and 3

3. “Viral fitness” in a host population primarily refers to:

1. Ability of a virus to cause the most severe clinical symptoms.
2. Capacity of a virus to replicate and transmit successfully between hosts.
3. Stability of the virus in laboratory freezers.
4. Number of mutations per replication cycle.

4. In many viral respiratory infections, “superspreading” can be facilitated by all of the following, EXCEPT:

1. Closed, crowded indoor settings with poor ventilation.
2. High viral load in the index case at the time of exposure.
3. Large gatherings with prolonged close contact.
4. Strict adherence to masking and distancing by all attendees.

5. In the natural course of many acute viral infections, which of the following immune components usually appears earliest?

1. High-affinity IgG antibodies
2. Innate interferon response
3. Long-lived plasma cells in bone marrow
4. Memory B cells

6. Which of the following is the most appropriate reason why some viruses cause persistent low-level infections without being cleared?

1. They lack any antigens recognizable by the immune system.
2. They may integrate into host genome or hide in immune-privileged sites, evading full immune elimination.
3. They are completely inert and do not replicate in the host.
4. They instantly kill all infected cells making immune recognition impossible.

7. In evaluating a new viral vaccine, “safety signal” in post-licensure surveillance most appropriately refers to:

1. Any report of mild pain at injection site.
2. A pattern suggesting a possible association between the vaccine and an adverse event that needs further investigation.
3. Confirmation that the vaccine has no side effects.
4. Only laboratory-confirmed cases of vaccine failure.

8. For a virus transmitted mainly through blood transfusion, which of the following control measures is most directly effective?

1. Chlorination of public water supply.
2. Screening all donated blood for viral markers before transfusion.
3. Indoor residual spraying of insecticides.
4. Use of face masks in crowded markets.

9. In the context of antiviral drug development, a “high genetic barrier to resistance” means:

1. The drug is too large to enter host cells.
2. Multiple viral mutations are required before clinically significant resistance appears.
3. The virus cannot mutate under any circumstances.
4. The drug targets only host factors and not viral proteins.

10. For a viral disease with both animal and human reservoirs, which of the following strategies is most consistent with the “One Health” approach?

1. Focusing only on treatment of human cases.
2. Integrating surveillance and control in humans, domestic animals, wildlife, and environment.
3. Eliminating all wildlife species that might harbor the virus.
4. Relying solely on international travel bans.