What should be done if a vaccine is accidentally frozen?

When a vaccine is accidentally frozen, the appropriate course of action is to discard the vaccine. Freezing can significantly affect the stability and efficacy of many vaccines, leading to potential loss of their immunogenicity. Once a vaccine has been frozen, even if it is subsequently thawed, it may not provide the protection that is expected because the active components may have been damaged.

Regulatory guidelines and manufacturer instructions typically dictate that any vaccine that has been exposed to freezing temperatures must not be used, as administering a compromised vaccine could lead to insufficient immune responses in patients. Therefore, the correct action is to ensure patient safety and the integrity of the vaccination program by discarding the affected vaccine.