Before packing a vaccine carrier for an outreach session using freeze-sensitive vaccines such as pentavalent, the health worker must condition the ice packs. Conditioning means:
- A Wiping the ice packs with disinfectant to prevent contamination of vials
- B Placing the ice packs in the refrigerator for 2 hours to reduce their temperature slightly
- C Allowing ice packs to stand at room temperature until a thin film of water forms on their surface ✓
- D Wrapping each ice pack in cloth before placing it around the vaccines
Correct answer: C. Allowing ice packs to stand at room temperature until a thin film of water forms on their surface
Explanation
Freshly removed ice packs are well below 0 degrees B and will freeze any vaccine touching them. Ice packs are therefore left at room temperature until a thin film of water appears on the surface and the ice core slides freely inside. This raises their contact temperature to about 0 degrees B, protecting freeze-sensitive vaccines like DPT, pentavalent, Td and hepatitis C during transport. Wrapping in cloth alone does not reliably prevent freezing.
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.