Question 1

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

Accepted Answer

They induce an antiviral state in neighboring cells by upregulating genes that inhibit viral replication.

Question 2

Natural Killer (NK) cells are activated in the absence of which molecule on the surface of target cells?

Accepted Answer

MHC class I

Question 3

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

Accepted Answer

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

Question 4

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

Accepted Answer

Inflammation → IFN release → NK cell activation

Question 5

Which cytokines are primarily responsible for triggering inflammation during the innate immune response?

Accepted Answer

Interleukin-1 (IL-1) and Tumor Necrosis Factor-alpha (TNF-α)

Question 6

Which of the following best describes the activation of a CD8+ T cell?

Accepted Answer

Recognition of antigen presented by MHC class I molecules on infected cells, along with co-stimulatory signals.

Question 7

A T-dependent B cell response requires which of the following interactions?

Accepted Answer

Interaction between B cell and helper T cell via CD40-CD40L and cytokine signaling.

Question 8

How do antibodies produced by B cells help protect against viral diseases?

Accepted Answer

By neutralizing viruses, preventing their entry into host cells, and marking them for destruction by phagocytes.

Question 9

Which of the following is an example of a current mRNA vaccine and its correct administration schedule?

Accepted Answer

COVID-19 mRNA vaccine (e.g., Pfizer-BioNTech), administered intramuscularly in two doses spaced 3-4 weeks apart.

Question 10

Which of the following statements about vaccine-generated immunity is correct?

Accepted Answer

Vaccines can generate both humoral and cellular immune responses, leading to long-term protection.

Question 11

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

Accepted Answer

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

Question 12

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 13

A patient receives a vaccine and later is exposed to the pathogen. Which immune response is primarily responsible for the rapid elimination of the pathogen?

Accepted Answer

Secondary immune response involving memory B and T cells.

Question 14

Which of the following best explains why inflammation is a critical component of the innate immune response?

Accepted Answer

It increases blood flow and recruits immune cells to the site of infection.

Question 15

A researcher is studying the effect of a new antiviral drug on NK cell activity. Which assay would best measure NK cell-mediated cytotoxicity?

Accepted Answer

Measuring the release of perforin and granzymes from NK cells.

Question 16

Which of the following equations best represents the relationship between vaccine coverage ($$C$$), basic reproduction number ($$R_0$$), and herd immunity threshold ($$H$$)?

Accepted Answer

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

Question 17

A child is exposed to measles but is not vaccinated. Which of the following best explains why the child is at risk, even if most of the community is vaccinated?

Accepted Answer

If vaccination rates drop below the herd immunity threshold, outbreaks can still occur and put unvaccinated individuals at risk.

Question 18

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 19

Which of the following best describes the difference between T-dependent and T-independent B cell activation?

Accepted Answer

T-dependent activation requires help from T cells and leads to stronger, longer-lasting antibody responses.

Question 20

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

Accepted Answer

Cytotoxic T cells (CD8+)

Adaptive and Innate Immune Responses to Viruses & Vaccination: Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards