Which of the following vaccines must be frozen?

Zostavax, the shingles vaccine, is a live attenuated vaccine that must be stored in a freezer to maintain its potency. The specific storage requirement is crucial because live attenuated vaccines are more sensitive to temperature fluctuations. If Zostavax is not kept frozen, it could lose its effectiveness, rendering the vaccination ineffective in preventing shingles.

In contrast, the inactivated influenza vaccine does not require freezing; it can be stored in a refrigerator. Tdap, which is a combination vaccine that protects against tetanus, diphtheria, and pertussis, is also supplied refrigerated, not frozen. Live attenuated influenza vaccine does require cold storage but can be kept in a refrigerator rather than needing to be frozen.

This understanding of storage conditions is fundamental when administering vaccinations, as it ensures that each vaccine is given at its maximum effectiveness.