Question 1

Which of the following best describes the primary role of interferons (IFNs) in the innate immune response to intracellular viruses?

Accepted Answer

They induce an antiviral state in neighboring cells and activate immune cells such as NK cells.

Question 2

Natural Killer (NK) cells are able to recognize and kill virus-infected cells primarily by detecting:

Accepted Answer

The absence or reduced expression of MHC class I molecules on the surface of infected cells.

Question 3

Which of the following best explains how cytotoxic T lymphocytes (CD8+ T cells) kill virally infected cells?

Accepted Answer

By releasing perforin and granzymes that induce apoptosis in the target cell.

Question 4

A patient receives a vaccine that contains mRNA encoding the spike protein of a virus. Which of the following best describes the immune response generated by this vaccine?

Accepted Answer

The mRNA is translated into protein, which is presented on MHC class I molecules, activating cytotoxic T cells and stimulating antibody production.

Question 5

Which of the following is a common myth about mRNA vaccines, and what is the scientific reason it is incorrect?

Accepted Answer

Myth: mRNA vaccines alter your DNA. Science: mRNA does not enter the nucleus and cannot integrate into DNA.

Question 6

Why are high vaccination rates important for a population?

Accepted Answer

They help achieve herd immunity, reducing the spread of disease and protecting those who cannot be vaccinated.

Question 7

Which of the following steps is required for the activation of a T-dependent B cell?

Accepted Answer

Recognition of antigen by the B cell receptor, internalization and presentation on MHC class II, and interaction with a helper T cell.

Question 8

A patient is exposed to a virus for the first time. Which of the following best describes the sequence of events in the innate immune response?

Accepted Answer

Release of interferons, activation of NK cells, and induction of inflammation.

Question 9

Which of the following is a key function of inflammation during a viral infection?

Accepted Answer

To increase blood flow and recruit immune cells to the site of infection.

Question 10

A new vaccine is administered intramuscularly and is found to generate both humoral and cellular immunity. Which of the following best explains why this vaccine is effective?

Accepted Answer

It stimulates both B cells to produce antibodies and T cells to kill infected cells.

Question 11

Which of the following equations best represents the relationship between the basic reproduction number $R_0$ and the herd immunity threshold $H$?

Accepted Answer

$H = 1 - \frac{1}{R_0}$

Question 12

A patient with a genetic defect in MHC class I expression is most likely to have impaired function of which immune cell type?

Accepted Answer

Cytotoxic T cells (CD8+)

Question 13

Which of the following is NOT a scientifically supported reason for vaccine hesitancy?

Accepted Answer

Belief that vaccines cause autism, which has been disproven by multiple studies.

Question 14

During a viral infection, which cytokine is most likely to be produced early and is critical for activating NK cells?

Accepted Answer

Interferon-alpha (IFN-\alpha)

Question 15

Which of the following best describes the process by which a CD8+ T cell recognizes and kills a virally infected cell?

Accepted Answer

Recognition of viral peptide presented on MHC class I, followed by release of perforin and granzymes.

Question 16

A child receives the measles, mumps, and rubella (MMR) vaccine. Which type of vaccine is this and what type of immunity does it primarily generate?

Accepted Answer

Live attenuated vaccine; generates both humoral and cellular immunity.

Question 17

Which of the following is a multi-step process that leads to the production of antibodies after exposure to a T-dependent antigen?

Accepted Answer

Antigen binds B cell receptor, B cell presents antigen on MHC II, helper T cell activates B cell, B cell differentiates into plasma cell, plasma cell secretes antibodies.

Question 18

Which of the following statements about vaccine effectiveness is correct?

Accepted Answer

Vaccine effectiveness is the proportionate reduction in disease among the vaccinated group compared to the unvaccinated group.

Question 19

A person claims that 'natural infection is always better than vaccination.' Which of the following is the best scientific rebuttal to this claim?

Accepted Answer

Vaccination provides immunity without the risk of severe disease or complications associated with natural infection.

Adaptive and Innate Immune Responses to Viruses, Vaccines, and Vaccine Misinformation

Study Guide - Practice Questions

Study Guide - Flashcards