APHA IMMUNIZATION EXAM LATEST
UPDATE 2026|2027|A COMPREHENSIVE
REVIEW OF 300 PRACTICE QUESTIONS
WITH ANSWERS AND RATIONALES|
ASSURED PASS
SECTION 1: VACCINE-PREVENTABLE DISEASES AND EPIDEMIOLOGY (QUESTIONS
1–30)
1. Which disease was declared eradicated worldwide in 1980, allowing routine
vaccination to be discontinued?
A. Polio
B. Smallpox
C. Measles
D. Diphtheria
Rationale: Smallpox was declared eradicated by the WHO in 1980, making it the
first human disease eliminated through vaccination. Routine smallpox vaccination
ceased globally, though the virus is retained in two secure laboratories.
2. What is the primary mode of transmission for hepatitis B virus?
A. Fecal-oral
B. Respiratory droplets
C. Percutaneous or mucosal exposure to infectious blood or body fluids
D. Vector-borne
Rationale: HBV is transmitted through percutaneous (e.g., needlestick) or mucosal
exposure to infectious blood or body fluids. It is not transmitted via the fecal-oral
route.
,3. Herd immunity against measles requires what approximate vaccination
coverage rate?
A. 50–60%
B. 70–80%
C. 90–95%
D. 99–100%
Rationale: Measles is highly contagious (R₀ of 12–18). Achieving herd immunity
requires approximately 90–95% population immunity to interrupt transmission.
4. Which strain of influenza is NOT included in the standard quadrivalent
seasonal influenza vaccine?
A. Influenza A (H1N1)
B. Influenza A (H3N2)
C. Influenza B (Victoria lineage)
D. Influenza B (Yamagata lineage)
Rationale: The B/Yamagata lineage has not been detected circulating since March
2020. Current quadrivalent and trivalent vaccines no longer include the
B/Yamagata component.
5. Which serogroup of Neisseria meningitidis is most commonly associated with
outbreaks in the United States and is included in the Menace vaccine?
A. Serogroup C
B. Serogroup X
C. Serogroup B
D. Serogroup A
Rationale: While Menace covers A, C, W, and Y, serogroup C has historically been
associated with college campus outbreaks in the U.S. Serogroup B requires a
separate vaccine (Men).
6. What is a serious complication of pertussis infection in infants?
A. Apnea
B. Hepatitis
C. Renal failure
D. Arthritis
,Rationale: Infants with pertussis are at high risk for apnea, pneumonia, seizures,
and death. Apnea is a particularly dangerous complication in this age group.
7. Which pneumococcal vaccine is recommended as the primary vaccine for
adults 65 years and older who have not previously received a pneumococcal
conjugate vaccine?
A. PPSV23
B. PCV20 or PCV21
C. PCV13
D. PCV15 only
Rationale: Current ACIP recommendations favor PCV20 or PCV21 for adults 65 and
older who have not received a conjugate vaccine. PPSV23 is no longer the
preferred primary vaccine.
8. Recombinant zoster vaccine (RZV, Shingrix) is recommended for which
population?
A. All adults 19 years and older
B. Adults 50 years and older and immunocompromised adults 19 years and older
C. Only adults 65 years and older
D. Only adults with a history of chickenpox
Rationale: RZV is recommended for adults 50 years and older and for
immunocompromised adults 19 years and older, regardless of prior varicella
history.
9. Which vaccine-preventable disease is characterized by paroxysmal coughing
followed by a high-pitched inspiratory whoop?
A. Diphtheria
B. Pertussis
C. Measles
D. Mumps
Rationale: Pertussis (whooping cough) classically presents with paroxysms of
coughing followed by a high-pitched inspiratory whoop, though this presentation
is less common in infants and adults.
, 10. Chronic hepatitis B infection is defined as persistence of HBsAg for at least
how many months?
A. 1 month
B. 3 months
C. 6 months
D. 12 months
Rationale: Chronic HBV infection is defined as detection of HBsAg for 6 months or
longer. This distinguishes it from acute infection, which typically resolves within 6
months.
11. What is the most common complication of mumps infection in post-pubertal
males?
A. Encephalitis
B. Orchitis
C. Deafness
D. Pancreatitis
Rationale: Orchitis (inflammation of the testes) occurs in up to 30% of post-
pubertal males with mumps and can lead to testicular atrophy.
12. Which hepatitis virus is transmitted primarily through the fecal-oral route?
A. Hepatitis B
B. Hepatitis C
C. Hepatitis A
D. Hepatitis D
Rationale: Hepatitis A is transmitted via the fecal-oral route through
contaminated food, water, or close contact. It is the only common hepatitis virus
with this transmission mode.
13. What is the incubation period for influenza?
A. 1–2 hours
B. 1–4 days
C. 7–10 days
D. 2–3 weeks
Rationale: The incubation period for influenza is typically 1–4 days, with an
UPDATE 2026|2027|A COMPREHENSIVE
REVIEW OF 300 PRACTICE QUESTIONS
WITH ANSWERS AND RATIONALES|
ASSURED PASS
SECTION 1: VACCINE-PREVENTABLE DISEASES AND EPIDEMIOLOGY (QUESTIONS
1–30)
1. Which disease was declared eradicated worldwide in 1980, allowing routine
vaccination to be discontinued?
A. Polio
B. Smallpox
C. Measles
D. Diphtheria
Rationale: Smallpox was declared eradicated by the WHO in 1980, making it the
first human disease eliminated through vaccination. Routine smallpox vaccination
ceased globally, though the virus is retained in two secure laboratories.
2. What is the primary mode of transmission for hepatitis B virus?
A. Fecal-oral
B. Respiratory droplets
C. Percutaneous or mucosal exposure to infectious blood or body fluids
D. Vector-borne
Rationale: HBV is transmitted through percutaneous (e.g., needlestick) or mucosal
exposure to infectious blood or body fluids. It is not transmitted via the fecal-oral
route.
,3. Herd immunity against measles requires what approximate vaccination
coverage rate?
A. 50–60%
B. 70–80%
C. 90–95%
D. 99–100%
Rationale: Measles is highly contagious (R₀ of 12–18). Achieving herd immunity
requires approximately 90–95% population immunity to interrupt transmission.
4. Which strain of influenza is NOT included in the standard quadrivalent
seasonal influenza vaccine?
A. Influenza A (H1N1)
B. Influenza A (H3N2)
C. Influenza B (Victoria lineage)
D. Influenza B (Yamagata lineage)
Rationale: The B/Yamagata lineage has not been detected circulating since March
2020. Current quadrivalent and trivalent vaccines no longer include the
B/Yamagata component.
5. Which serogroup of Neisseria meningitidis is most commonly associated with
outbreaks in the United States and is included in the Menace vaccine?
A. Serogroup C
B. Serogroup X
C. Serogroup B
D. Serogroup A
Rationale: While Menace covers A, C, W, and Y, serogroup C has historically been
associated with college campus outbreaks in the U.S. Serogroup B requires a
separate vaccine (Men).
6. What is a serious complication of pertussis infection in infants?
A. Apnea
B. Hepatitis
C. Renal failure
D. Arthritis
,Rationale: Infants with pertussis are at high risk for apnea, pneumonia, seizures,
and death. Apnea is a particularly dangerous complication in this age group.
7. Which pneumococcal vaccine is recommended as the primary vaccine for
adults 65 years and older who have not previously received a pneumococcal
conjugate vaccine?
A. PPSV23
B. PCV20 or PCV21
C. PCV13
D. PCV15 only
Rationale: Current ACIP recommendations favor PCV20 or PCV21 for adults 65 and
older who have not received a conjugate vaccine. PPSV23 is no longer the
preferred primary vaccine.
8. Recombinant zoster vaccine (RZV, Shingrix) is recommended for which
population?
A. All adults 19 years and older
B. Adults 50 years and older and immunocompromised adults 19 years and older
C. Only adults 65 years and older
D. Only adults with a history of chickenpox
Rationale: RZV is recommended for adults 50 years and older and for
immunocompromised adults 19 years and older, regardless of prior varicella
history.
9. Which vaccine-preventable disease is characterized by paroxysmal coughing
followed by a high-pitched inspiratory whoop?
A. Diphtheria
B. Pertussis
C. Measles
D. Mumps
Rationale: Pertussis (whooping cough) classically presents with paroxysms of
coughing followed by a high-pitched inspiratory whoop, though this presentation
is less common in infants and adults.
, 10. Chronic hepatitis B infection is defined as persistence of HBsAg for at least
how many months?
A. 1 month
B. 3 months
C. 6 months
D. 12 months
Rationale: Chronic HBV infection is defined as detection of HBsAg for 6 months or
longer. This distinguishes it from acute infection, which typically resolves within 6
months.
11. What is the most common complication of mumps infection in post-pubertal
males?
A. Encephalitis
B. Orchitis
C. Deafness
D. Pancreatitis
Rationale: Orchitis (inflammation of the testes) occurs in up to 30% of post-
pubertal males with mumps and can lead to testicular atrophy.
12. Which hepatitis virus is transmitted primarily through the fecal-oral route?
A. Hepatitis B
B. Hepatitis C
C. Hepatitis A
D. Hepatitis D
Rationale: Hepatitis A is transmitted via the fecal-oral route through
contaminated food, water, or close contact. It is the only common hepatitis virus
with this transmission mode.
13. What is the incubation period for influenza?
A. 1–2 hours
B. 1–4 days
C. 7–10 days
D. 2–3 weeks
Rationale: The incubation period for influenza is typically 1–4 days, with an
