APHA Vaccine Schedules & Recommendations 3 — Questions and Answers
Question 1: What is the minimum interval between the first and second doses of the hepatitis A vaccine series?
- 4 weeks
- 6 months (Correct answer)
- 1 year
- 18 months
Correct answer: 6 months
The two-dose hepatitis A series requires a minimum interval of 6 months between doses for full seroconversion.
Question 2: Under the US immunization schedule, the rotavirus vaccine series must be completed by what maximum age?
- 8 months 0 days (Correct answer)
- 12 months
- 15 months
- 24 months
Correct answer: 8 months 0 days
Due to intussusception risk, no rotavirus vaccine doses should be initiated or given after 8 months 0 days of age.
Question 3: A 65-year-old adult who has never received pneumococcal vaccine should receive which vaccination sequence according to ACIP?
- PCV15 alone
- PPSV23 alone
- PCV15 followed by PPSV23 at least 1 year later, or PCV20 alone (Correct answer)
- PCV13 followed by PCV20
Correct answer: PCV15 followed by PPSV23 at least 1 year later, or PCV20 alone
ACIP recommends either PCV15 followed by PPSV23 (≥1 year later) or PCV20 alone for immunocompetent adults aged 65+.
Question 4: Which vaccine is contraindicated in pregnancy due to being a live attenuated virus vaccine?
- Tdap
- Influenza inactivated
- Varicella (Correct answer)
- Hepatitis B
Correct answer: Varicella
Varicella vaccine is a live attenuated vaccine and is contraindicated during pregnancy; it should be given postpartum if needed.
Question 5: The Hib (Haemophilus influenzae type b) vaccine series typically concludes with a booster dose at which age?
- 6 months
- 9 months
- 12–15 months (Correct answer)
- 18–24 months
Correct answer: 12–15 months
Depending on the brand used, the Hib booster dose is given at 12–15 months to complete the primary series.
Question 6: An unvaccinated 14-year-old initiating HPV vaccination today should receive how many doses?
- 1 dose
- 2 doses
- 3 doses (Correct answer)
- 4 doses
Correct answer: 3 doses
Individuals who initiate HPV vaccine at age 15 or older require 3 doses (0, 1–2, and 6 months); at 14 they are still in the 2-dose window if starting before age 15.
Question 7: Which influenza vaccine formulation is specifically approved only for adults aged 65 and older?
- Standard-dose inactivated IIV4
- High-dose inactivated IIV4 or adjuvanted IIV4 (aIIV4) (Correct answer)
- Live attenuated LAIV4
- Recombinant RIV4 in any dose
Correct answer: High-dose inactivated IIV4 or adjuvanted IIV4 (aIIV4)
High-dose (HD-IIV4) and adjuvanted (aIIV4) influenza vaccines are preferentially recommended for adults ≥65 years due to enhanced immunogenicity.
APHA Vaccine Schedules & Recommendations 3
What is the minimum interval between the first and second doses of the hepatitis A vaccine series?