Which vaccine has been correctly stored in the fridge?

The vaccine that is stored correctly is the one placed in a labeled container on the middle shelf of the fridge. This option reflects best practices for vaccine storage, as maintaining a consistent temperature is critical for preserving the efficacy of vaccines.

The middle shelf is typically the most stable area in a fridge, where temperatures are less susceptible to fluctuation caused by frequent opening and closing of the door. Proper labeling also ensures that vaccines can be easily identified and helps to prevent mix-ups, which is crucial in a clinical setting.

In contrast, storing a vaccine in a drawer could lead to an environment that might not maintain the ideal temperature range. Storing two different vaccines in the same container poses a risk of confusion and potential cross-contamination or administrative errors. Storing a vaccine in the fridge door is generally discouraged as the temperature can fluctuate more significantly there due to the door being opened frequently, thus compromising the vaccine's integrity.