Question 1

B cells in the germinal centers of the tonsils predominantly produce which type of antibody?
A) IgA
B) IgE
C) IgG
D) IgM

Accepted Answer

The B cells of the tonsils predominantly produce IgG, rather than IgA, as would be expected at a mucosal surface.

Question 2

Peyer's patches are located in the:
A) Bronchial tree
B) Urogenital tract
C) Back of the throat
D) Gastrointestinal (GI) tract

Accepted Answer

Peyer's patches are mucosal-associated lymphoid tissue (MALT) located along the GI tract, an area that is frequently exposed to pathogens.

Question 3

Lipopolysaccharide (LPS) is an example of a(n):
A) Toxoid
B) Exotoxin
C) Endotoxin
D) Enterotoxin

Accepted Answer

LPS is an integral component of the gram negative cell wall, so it is designated as an endotoxin. When the bacterium dies, the LPS is released, which can lead to endotoxic shock.

Question 4

Which of the following adjuvants is/are capable of enhancing mucosal immunity? 
I. Squalene
II. Cholera toxin
III. Monophosphoryl lipid A
A) I only
B) III only
C) I and II
D) II and III
E) I, II, and III

Accepted Answer

Squalene is an adjuvant that enhances systemic immunity, while bacterial toxins, such as cholera toxin, and monophosphoryl lipid A can enhance mucosal immune responses.

Question 5

What is the purpose of adding an adjuvant to a vaccine?
A) To reduce side effects
B) To enhance the immune response
C) To lower risk of allergic reactions
D) To prevent microbial contamination

Accepted Answer

Several types of adjuvants could be added to a vaccine to enhance the immune response. For example, aluminum salts may be added to an intramuscular injection to form an insoluble depot preparation that is slowly released. The slow release allows for an extended exposure to the pathogenic antigens, and, subsequently, a stronger immune response.

Question 6

Which of the following is an advantage of live, attenuated vaccination over other types of vaccination?
A) Inexpensive to make
B) One dose produces immunity
C) Always stimulate mucosal and systemic immunity
D) Pose no health risks to immunosuppressed individuals

Accepted Answer

The live, attenuated vaccine takes only one dose to produce immunity because it has the ability to replicate within the host and stimulate a vigorous immune response. However, the mucosal immunity is often not stimulated, and vaccines may cause infection in immunocompromised individuals who are exposed to anyone that received a live, attenuated vaccine.

Question 7

Why do adenovirus vaccine vectors have limited utility?
A) Adenoviruses are small and cannot incorporate large numbers of genes from other viruses.
B) Most humans have preexisting antibodies that neutralize the vector before it can reach target tissue.
C) The immune response is weaker because the vector displays antigens from both the adenovirus and the pathogenic virus, diluting the immune response.
D) If the adenovirus incorporates large numbers of genes from pathogenic viruses, it may lose the ability to infect host tissue and elicit an immune response.

Accepted Answer

Adenoviruses may be of some use as vectors for carrying antigens of pathogens, but most humans possess preexisting antibodies because of frequent exposure to adenoviruses. Therefore, the preexisting antibodies neutralize the adenovirus and target it for elimination by phagocytosis before a systemic immune response to the new antigens can be mounted. These barriers must be overcome before adenoviruses can be widely used in vaccination.

Question 8

Which type of vaccine may revert to a virulent form of the organism?
A) Cholera vaccine
B) Pertussis vaccine
C) Salk polio vaccine
D) Influenza vaccine (subcutaneous version)

Accepted Answer

From the list, only the cholera vaccine is a live, attenuated vaccine, which may revert to a more virulent form even though modifications were made to eliminate virulence factors.

Question 9

Which of the following is an example of a virulence factor?
A) Host cell cilia
B) Viral subunits
C) Bacterial DNA
D) Polysaccharide capsule

Accepted Answer

The bacterial polysaccharide capsule is considered a virulence factor because it protects the bacteria from host immunity.

Question 10

What is the difference between Freund's Incomplete Adjuvant (FIA) and Freund's Complete Adjuvant (FCA)?
A) FIA does not contain water.
B) FIA does not contain mineral oil.
C) FIA does not contain killed mycobacteria.
D) FIA does not contain mannide monooleate.

Accepted Answer

FIA does not contain the killed mycobacteria component that causes inflammatory reactions, ulcerations, and granulomas at the injection site. However, the immune response is limited to an antibody response rather than a cell-mediated response with FIA, but FIA can be used in humans.

Question 11

Why are toxoid vaccines an effective means for reducing bacterial illness?
A) The toxin causes the damage, not the bacteria.
B) Bacteria have to die before the toxins can cause damage.
C) The toxins stimulate the immune system better than bacteria.
D) Bacteria have the toxins on their surface, so an immune response to the toxins will neutralize both.

Accepted Answer

Toxoid vaccines are effective because the toxin causes the damage to the host, not the bacteria that released the toxin. By stimulating the immune system to produce antibodies to the toxin, the toxin will be neutralized before it can harm the host. As all toxins are not endotoxins, bacteria do not always have to die before the toxin is released. And even though the immune response to the toxin is no greater than a potential response to the bacteria, the toxin is the main damaging agent, and focusing the immune response on the toxin significantly reduces host illness.

Question 12

Which of the following is a conjugate vaccine?
A) Sabin polio
B) Hepatitis A
C) Rotavirus vaccine
D) Pneumococcal vaccine

Accepted Answer

The pneumococcal vaccine is an example of a conjugate vaccine. To elicit a T cell-dependent response and generation of memory cells, capsular polysaccharides are conjugated to another agent that provides better immunogenicity.

Question 13

Which type of vaccine involves culturing both noninfective and infective viruses together to produce a noninfective vaccine agent with the antigens of the infective virus?
A) Subunit vaccines
B) Conjugate vaccines
C) Reassortment vaccines
D) Recombinant viral vaccines

Accepted Answer

Reassortment vaccines contain a noninfective virus that expresses antigens from multiple human and animal strains of the same virus. For example, a chicken egg can be infected with two different viruses. One strain can infect man, while the other strain is noninfective, but grows well in eggs. The genetic rearrangements of the viruses growing in the egg produce a virus that expresses the antigens from the infective virus but is noninfective and grows well in eggs. This reassortment virus would be selected for use in the vaccine.

Question 14

Which of the following pose little or no risk to immunocompromised individuals? 
I. Subunit vaccine
II. Inactivated vaccine
III. Live, attenuated vaccine
A) I only
B) III only
C) I and II
D) II and III
E) I, II, and III

Accepted Answer

Only live, attenuated vaccines pose the risk of reverting to a more virulent form, which poses a risk of infection of immunocompromised individuals who come into contact with a person who has received the vaccine.

Question 15

Which of the following is true concerning excipients in vaccines? 
I. Excipients can cause allergic reactions.
II. Excipients may be purposefully added to vaccines.
III. Excipients may be contaminants from the manufacturing process.
A) I only
B) III only
C) I and II
D) II and III
E) I, II, and III

Accepted Answer

Excipients may be contaminants from the manufacturing process, such as yeast or egg protein, or they may be added purposefully, such as with antimicrobials to prevent microbial contamination. These added components have the potential to cause allergic reactions in recipients.

Quiz 24: Vaccines in Theory and Practice

B cells in the germinal centers of the tonsils predominantly produce which type of antibody?

Peyer's patches are located in the:

Lipopolysaccharide (LPS) is an example of a(n) :

Which of the following adjuvants is/are capable of enhancing mucosal immunity? I. Squalene II. Cholera toxin III. Monophosphoryl lipid A

What is the purpose of adding an adjuvant to a vaccine?

Which of the following is an advantage of live, attenuated vaccination over other types of vaccination?

Why do adenovirus vaccine vectors have limited utility?

Which type of vaccine may revert to a virulent form of the organism?

Which of the following is an example of a virulence factor?

What is the difference between Freund's Incomplete Adjuvant (FIA) and Freund's Complete Adjuvant (FCA) ?

Why are toxoid vaccines an effective means for reducing bacterial illness?

Which of the following is a conjugate vaccine?

Which type of vaccine involves culturing both noninfective and infective viruses together to produce a noninfective vaccine agent with the antigens of the infective virus?

Which of the following pose little or no risk to immunocompromised individuals? I. Subunit vaccine II. Inactivated vaccine III. Live, attenuated vaccine

Which of the following is true concerning excipients in vaccines? I. Excipients can cause allergic reactions. II. Excipients may be purposefully added to vaccines. III. Excipients may be contaminants from the manufacturing process.