How long is the powder part of the ProQuad vaccine supposed to be stored?

The powder part of the ProQuad vaccine, which contains a mixture of live attenuated viruses for measles, mumps, rubella, and varicella, is intended to be stored in a freezer. Specifically, this storage condition is crucial because the live virus component remains stable and effective at low temperatures, preventing degradation or loss of potency.

Storing it at room temperature or in a fridge would expose the vaccine to higher temperatures, which could lead to a decrease in its effectiveness. Similarly, using a cooler without the proper control of temperature might not guarantee that the vaccine is kept at the necessary freezing conditions. Therefore, maintaining the powder part in a freezer is essential for ensuring its viability and efficacy when administered.