A cold chain technician finds that a vial of DPT vaccine has been accidentally frozen and thawed. The correct action is to:
- A Discard the vial as DPT is damaged by freezing ✓
- B Use the vial immediately as freezing does not affect DPT potency
- C Return the vial to the ILR and use it within 28 days
- D Warm the vial to room temperature and use it
Correct answer: A. Discard the vial as DPT is damaged by freezing
Explanation
DPT vaccine is an aluminum-adjuvanted vaccine and is damaged by freezing. Freezing causes the aluminum adjuvant to flocculate and lose its immunogenicity. Any frozen DPT vial must be discarded. The shake test can confirm freezing damage, but the vial should not be used.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.