Question 1

Which of the following best describes the principle behind herd immunity?

Accepted Answer

It is the phenomenon where a high percentage of immune individuals in a population indirectly protects non-immune individuals from infection.

Question 2

Which of the following statements about live attenuated vaccines is CORRECT?

Accepted Answer

They often provide longer-lasting immunity with fewer booster shots compared to inactivated vaccines.

Question 3

A patient receives a vaccine that contains only the purified surface protein of a virus produced using recombinant DNA technology. Which type of vaccine did the patient receive?

Accepted Answer

Subunit vaccine

Question 4

Which of the following best explains why adjuvants are added to some vaccines?

Accepted Answer

To enhance the body's immune response to the antigen

Question 5

A diagnostic test for a viral infection has a sensitivity of 95% and a specificity of 90%. What does the sensitivity value indicate?

Accepted Answer

The test correctly identifies 95% of people who have the infection.

Question 6

Which of the following is a major advantage of nucleic acid vaccines compared to traditional vaccines?

Accepted Answer

They can induce both humoral and cellular immunity without using the whole pathogen.

Question 7

A laboratory is using an ELISA to detect antibodies against HIV in patient serum. Which of the following best describes the principle of the indirect ELISA?

Accepted Answer

Antigen is bound to the well, patient antibody binds to antigen, and a secondary enzyme-linked antibody binds to the patient antibody.

Question 8

Which of the following best describes a toxoid vaccine?

Accepted Answer

A vaccine containing inactivated toxins that stimulate an immune response without causing disease.

Question 9

A patient’s antibody titer against a specific pathogen increases significantly over a two-week period. What does this most likely indicate?

Accepted Answer

The patient is experiencing a secondary immune response, possibly due to recent exposure or vaccination.

Question 10

Which of the following is a key reason why antibody-antigen complexes are ideal for diagnostic tests?

Accepted Answer

They form specific and stable interactions that can be easily measured.

Question 11

Which of the following is an example of a direct agglutination reaction?

Accepted Answer

Mixing patient serum with red blood cells to observe clumping.

Question 12

Which of the following statements about monoclonal antibodies is TRUE?

Accepted Answer

They are produced by a single clone of B cells and are specific to one epitope.

Question 13

A new vaccine is developed using a harmless virus engineered to express antigens from a pathogenic virus. Which type of vaccine does this describe?

Accepted Answer

Virus-like particle vaccine

Question 14

Which of the following best describes the difference between direct and indirect ELISA?

Accepted Answer

Direct ELISA detects antigen using a labeled primary antibody, while indirect ELISA detects antibody using a labeled secondary antibody.

Question 15

Which of the following is a potential disadvantage of live attenuated vaccines?

Accepted Answer

They may revert to a virulent form in rare cases.

Question 16

Which of the following best explains why vaccine safety is a controversial topic?

Accepted Answer

Public concerns about rare adverse effects and misinformation can lead to vaccine hesitancy.

Question 17

A child receives a conjugated vaccine. What is the main advantage of this type of vaccine for young children?

Accepted Answer

It combines a weak antigen with a strong protein carrier to enhance the immune response.

Question 18

Which of the following best describes hemagglutination?

Accepted Answer

The clumping of red blood cells due to specific antibody-antigen interactions.

Question 19

A patient is given a vaccine and later exposed to the pathogen. The immune response is rapid and robust. Which concept does this scenario best illustrate?

Accepted Answer

Secondary immune response

Question 20

Which of the following is a benefit of using ELISA in diagnostic testing?

Accepted Answer

It provides quantitative results and can be automated for high-throughput screening.

Chapter 18: Practical Applications of Immunology – Vaccines and Immunological Diagnostics

Study Guide - Practice Questions

Study Guide - Flashcards