Question 1

Which of the following best describes an attenuated vaccine?

Accepted Answer

A vaccine containing weakened pathogens that can replicate but do not cause disease in healthy individuals.

Question 2

Which equation best represents the calculation of vaccine effectiveness ($$VE) in a $$population?

Accepted Answer

$$VE = \frac{(AR_{unvaccinated} - AR_{vaccinated})}{AR_{unvaccinated}} 	imes 100$$

Question 3

A patient receives a vaccine that contains only the capsid protein of Hepatitis B virus produced in yeast. Which type of vaccine is this?

Accepted Answer

Subunit vaccine

Question 4

Which of the following is a major risk associated with live attenuated vaccines in immunocompromised patients?

Accepted Answer

Reversion to a virulent form causing disease

Question 5

Which of the following statements about dengue virus is correct?

Accepted Answer

It is a spherical, enveloped, single-stranded RNA virus.

Question 6

Antibody-dependent enhancement (ADE) in dengue infection occurs when:

Accepted Answer

Antibodies from a previous infection bind to a different strain and facilitate viral entry into host cells.

Question 7

Which of the following is a common treatment for malaria?

Accepted Answer

Doxycycline

Question 8

A child presents with muscle spasms and lockjaw after a puncture wound. Which pathogen is most likely responsible?

Accepted Answer

Clostridium tetani

Question 9

Which of the following best explains why the BCG vaccine is not recommended for immunocompromised children?

Accepted Answer

It is a live, attenuated vaccine and may cause disease in immunocompromised hosts.

Question 10

Which diagnostic test is most specific for active tuberculosis infection?

Accepted Answer

Culture of Mycobacterium tuberculosis from sputum

Question 11

Which of the following is a mechanism by which COVID-19 evades host immunity?

Accepted Answer

Antigenic drift enables invasion of host antibodies.

Question 12

Which vaccine type uses mRNA technology to encode spike protein and induce immunity against COVID-19?

Accepted Answer

mRNA vaccine

Question 13

A patient with severe COVID-19 develops acute respiratory distress and a cytokine storm. Which immune response is most likely responsible?

Accepted Answer

Excessive activation of T cells and release of pro-inflammatory cytokines

Question 14

Which of the following is a correct statement about the use of adjuvants in vaccines?

Accepted Answer

Adjuvants are added to vaccines to improve immune effectiveness by enhancing antigen presentation.

Question 15

Which of the following is a plausible consequence of using polysaccharide vaccines made from molecules in pathogen capsules?

Accepted Answer

They have low immunogenicity and may require conjugation to proteins to enhance immune response.

Question 16

A researcher uses CRISPR gene editing to prevent mosquitoes from reproducing. Which disease could this strategy help control?

Accepted Answer

Dengue

Question 17

Which of the following is a distinguishing feature of Mycobacterium tuberculosis compared to other bacteria?

Accepted Answer

It has a 20-hour generation time and is acid-fast due to mycolic acids in its cell wall.

Question 18

Which of the following best describes the pathogenesis of tetanus?

Accepted Answer

Release of tetanospasmin toxin blocks inhibitory neurotransmitter release, leading to muscle spasms.

Question 19

Which formula best represents the calculation of the basic reproduction number ($$R_0) $$for an infectious disease?

Accepted Answer

$$R_0$$ = \frac{	ext{number of secondary cases}}{	ext{number of primary cases}}$$

Question 20

Which of the following is a reason why inactivated vaccines often require booster shots?

Accepted Answer

They do not replicate in the host and therefore produce a weaker immune response.

Vaccines and Major Infectious Diseases: Microbiology Study Notes

Study Guide - Practice Questions