A cold chain technician finds that OPV vials have been accidentally stored at -25°C for 48 hours. The correct action is:
- A Use the vials as OPV is freeze-tolerant and unaffected by freezing ✓
- B Discard all OPV vials immediately
- C Perform shake test and discard if flocculate forms
- D Transfer to 2–8°C and check VVM before use
Correct answer: A. Use the vials as OPV is freeze-tolerant and unaffected by freezing
Explanation
OPV is a freeze-tolerant vaccine and can be safely stored at temperatures well below freezing without losing potency. In fact, for long-term storage, OPV is stored frozen at -15 to -25°C. The shake test (to detect freeze damage) applies only to freeze-sensitive vaccines: DPT, DT, TT, Hepatitis B, Pentavalent, and liquid Hib. If flocculate (aggregated particles) persists after shaking freeze-sensitive vaccines, they must be discarded. BCG, OPV, and MMR are freeze-tolerant.
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.