APHA Immunization Pharmacology & Vaccine Science 2 — Questions and Answers
Question 1: Which immune cells are the primary producers of antibodies following vaccination?
- Plasma B cells (Correct answer)
- CD8+ cytotoxic T cells
- Natural killer (NK) cells
- Macrophages
Correct answer: Plasma B cells
Plasma B cells are differentiated B lymphocytes that are the primary source of circulating antibodies after antigen stimulation from vaccination.
Question 2: What is seroconversion in the context of immunization?
- Development of detectable antibodies following vaccination or infection (Correct answer)
- Conversion from live attenuated to inactivated vaccine formulation
- A patient changing from one vaccine brand to a competing brand
- Loss of immunity due to waning antibody titers
Correct answer: Development of detectable antibodies following vaccination or infection
Seroconversion refers to the point at which a person develops a detectable level of antibodies in response to vaccination or natural infection.
Question 3: Why are live attenuated vaccines generally contraindicated in severely immunocompromised patients?
- The attenuated pathogen can replicate and cause disease in the absence of normal immune defenses (Correct answer)
- They contain higher antigen loads that overwhelm a weakened immune system
- They require intact innate immunity to stimulate the adaptive response
- The adjuvants in live vaccines are toxic to immunocompromised individuals
Correct answer: The attenuated pathogen can replicate and cause disease in the absence of normal immune defenses
In severely immunocompromised patients, live attenuated organisms can replicate unchecked and cause vaccine-strain disease due to absent or deficient immune defenses.
Question 4: Which vaccine component is responsible for a local injection site reaction such as redness and swelling?
- Adjuvants like aluminum salts that stimulate local innate immune activation (Correct answer)
- Preservatives like thimerosal that cause tissue irritation
- The antigen protein, which directly damages muscle fibers
- Stabilizers like gelatin that cause allergic inflammation
Correct answer: Adjuvants like aluminum salts that stimulate local innate immune activation
Aluminum-based adjuvants trigger local innate immune activation, resulting in the classic injection site reactions of erythema, swelling, and tenderness.
Question 5: What is the significance of herd immunity threshold in community vaccination programs?
- It is the vaccination coverage level at which pathogen spread is interrupted, protecting unvaccinated individuals (Correct answer)
- It is the minimum antibody titer needed for individual protection
- It defines the maximum number of adverse events acceptable per 100,000 doses
- It is the point at which natural infection provides the same protection as vaccination
Correct answer: It is the vaccination coverage level at which pathogen spread is interrupted, protecting unvaccinated individuals
The herd immunity threshold is the proportion of a population that must be immune to stop disease transmission and protect those who cannot be vaccinated.
Question 6: Which type of vaccine is most appropriate for a patient who is 8 weeks pregnant and needs protection against influenza?
- Inactivated influenza vaccine (IIV) (Correct answer)
- Live attenuated influenza vaccine (LAIV)
- Recombinant influenza vaccine (RIV) is the only option
- No influenza vaccine should be given during pregnancy
Correct answer: Inactivated influenza vaccine (IIV)
Inactivated influenza vaccine (IIV) is safe and recommended throughout pregnancy; LAIV is contraindicated due to its live attenuated viral components.
APHA Immunization Pharmacology & Vaccine Science 2
Which immune cells are the primary producers of antibodies following vaccination?