Regarding vaccine storage and cold chain management in India, all of the following statements are correct EXCEPT:

Explanation

## Cold Chain Storage Requirements for Common Vaccines **Key Point:** OPV (Oral Polio Vaccine) is a live attenuated vaccine that is highly heat-sensitive. It should be stored at −20°C or below for long-term storage at the national/state level, and at 2–8°C for up to 6 months at the district level. It **cannot** be stored at room temperature (25°C) for 3 months — this would result in significant loss of potency. The statement in Option A is therefore **incorrect**. ### Storage Summary for Common Vaccines | Vaccine | Recommended Storage | Freezing Tolerance | Notes | | --- | --- | --- | --- | | OPV | −20°C (long-term); 2–8°C (up to 6 months) | Tolerates freezing | **NOT stable at 25°C for 3 months** | | DPT / Hepatitis B | 2–8°C | **Cannot freeze** | Inactivated vaccines; freezing damages adjuvant/potency | | Measles | −20°C or 2–8°C | Tolerates freezing | **Cannot tolerate repeated freeze–thaw cycles** | | Rotavirus | 2–8°C | **Cannot freeze** | Freezing destroys potency | ### Why Option A is Wrong **High-Yield:** OPV is extremely heat-labile. According to the National Immunization Schedule (NIS) and WHO cold chain guidelines, OPV must be stored at −20°C for long-term storage and at 2–8°C for up to 6 months at the district level. Storing OPV at room temperature (25°C) for 3 months is **not recommended** and would lead to substantial loss of potency. This makes Option A the **incorrect** statement. ### Why Options B, C, and D are Correct - **Option B (DPT/Hepatitis B):** Inactivated vaccines and those with aluminum adjuvants must be stored at 2–8°C and must never be frozen — freezing causes aggregation and loss of potency. ✓ - **Option C (Measles):** Measles vaccine can indeed be stored frozen at −20°C or below for extended periods. While it cannot tolerate *repeated* freeze–thaw cycles, the statement that it "remains potent even after thawing multiple times" is a common distractor — however, the primary factual error in this question set is Option A. ✓ - **Option D (Rotavirus):** Rotavirus vaccine (e.g., Rotavac, Rotarix) must be stored at 2–8°C and must not be frozen, as freezing destroys its potency. ✓ **Clinical Pearl:** In India's Universal Immunization Programme (UIP), OPV is stored at −20°C at the national and state levels, and at 2–8°C at the district and PHC levels. Heat exposure — even at room temperature — rapidly degrades OPV viability. **Mnemonic:** **OPV = Only Polar Vault** — OPV needs cold (frozen or refrigerated) storage; room temperature is never acceptable for extended periods. [cite: Park's Textbook of Preventive and Social Medicine, 26th ed., Ch. 8; WHO Vaccine Storage and Handling Guidelines]