APHA Cold Chain Management & Vaccine Storage 2 — Questions and Answers
Question 1: A refrigerator unit is found with a minimum/maximum thermometer reading of 1°C min and 11°C max over the weekend. What is the correct response?
- Continue using all vaccines since the average is within range
- Quarantine all vaccines and contact the state immunization program for guidance (Correct answer)
- Discard all vaccines immediately without further assessment
- Reset the thermometer and continue normal operations
Correct answer: Quarantine all vaccines and contact the state immunization program for guidance
Temperatures outside the 2–8°C range require quarantining affected vaccines and consulting the state or local immunization program before use or discard.
Question 2: Which of the following vaccine types is MOST sensitive to freezing temperatures?
- Live attenuated influenza vaccine (LAIV)
- Varicella vaccine
- Hepatitis B vaccine (Correct answer)
- MMR vaccine
Correct answer: Hepatitis B vaccine
Hepatitis B vaccine is a killed/inactivated vaccine that is highly sensitive to freezing, which permanently damages the adjuvant and renders it ineffective.
Question 3: What is the recommended placement of vaccines within a refrigerator unit to maintain proper cold chain?
- Store on the door shelves for easy access
- Store directly against the back wall for maximum cooling
- Store on middle shelves away from walls, floor, and door (Correct answer)
- Store on the bottom shelf where cold air settles
Correct answer: Store on middle shelves away from walls, floor, and door
Vaccines should be stored on middle shelves away from unit walls, floor, and doors to avoid temperature extremes and air circulation issues.
Question 4: A continuous electronic temperature monitoring device (data logger) should have a reading interval no greater than:
- 60 minutes
- 30 minutes (Correct answer)
- 10 minutes
- 5 minutes
Correct answer: 30 minutes
CDC recommends data loggers record temperatures at intervals no greater than 30 minutes to ensure excursions are detected promptly.
Question 5: When receiving a vaccine shipment, which action should be performed FIRST?
- Check expiration dates on all vials
- Inspect packaging for signs of temperature excursion using indicators (Correct answer)
- Count the number of doses received against the invoice
- Immediately place all vaccines in the refrigerator
Correct answer: Inspect packaging for signs of temperature excursion using indicators
Inspecting the shipping container and temperature indicators first determines whether the cold chain was maintained during transport before any other action.
Question 6: Which of the following is the primary purpose of placing water bottles in an empty vaccine refrigerator?
- To add moisture and prevent vaccine vials from drying out
- To act as thermal mass and reduce temperature fluctuations (Correct answer)
- To indicate when the freezer section is too cold
- To block airflow and keep vaccines from touching the back wall
Correct answer: To act as thermal mass and reduce temperature fluctuations
Water bottles serve as thermal mass (buffer), stabilizing temperatures and slowing temperature rises during power outages or door openings.
Question 7: According to CDC guidance, vaccine storage units should be dedicated refrigerators/freezers. If a combination (dorm-style) unit must be used, which vaccines should NEVER be stored in it?
- Hepatitis A vaccine
- Influenza vaccine
- Varicella and MMRV vaccines (Correct answer)
- Meningococcal conjugate vaccines
Correct answer: Varicella and MMRV vaccines
Varicella and MMRV vaccines require frozen storage, and dorm-style units cannot reliably maintain freezer temperatures, posing high risk of freeze-thaw damage.
APHA Cold Chain Management & Vaccine Storage 2
A refrigerator unit is found with a minimum/maximum thermometer reading of 1°C min and 11°C max over the weekend.
What is the correct response?