In a refrigerator, why should vaccines not be stored on the door shelves?

• A. Because the middle of the fridge provides more stable temperature.
• B. Door shelves are cooler.
• C. Door shelves are more humid.
• D. Door shelves are where labels are stored.

Answer: (A)

Vaccines must be kept within a narrow, consistent temperature range to maintain potency. The door of a refrigerator is where temperature fluctuates the most—every time you open it, warm room air rushes in and the contents near the door experience temperature ups and downs. The middle of the fridge stays farther from the door and away from air drafts, so it maintains a more stable temperature. Storing vaccines there minimizes the risk of temperature excursions that could reduce efficacy. The door shelves aren’t cooler; they’re more variable. Humidity or label storage aren’t the main issues for vaccine potency.