Vaccine Types and Cold Chain

A 4-year-old child attends the immunisation clinic for catch-up vaccination. The health worker retrieves a vial of inactivated polio vaccine (IPV) that has been stored in the cold chain for 18 months. The vial label is partially illegible, and there is uncertainty about whether the vaccine has been exposed to freezing temperatures at any point. Which investigation is most appropriate to assess whether this vaccine vial should be used or discarded?

During a vaccine cold chain audit in a district immunization center in Uttar Pradesh, the supervisor identifies that the most common reason for vaccine wastage is improper temperature monitoring. Which of the following is the MOST COMMON cause of cold chain failure in Indian primary health centers?

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

Which feature best distinguishes inactivated polio vaccine (IPV) from oral polio vaccine (OPV) in the context of India's immunisation programme?

A 6-month-old infant in rural Maharashtra is brought for routine immunisation. The health worker notes that the vaccine vial of rotavirus vaccine has been left on the shelf at room temperature (28°C) for 4 hours after opening. Which feature best distinguishes rotavirus vaccine from measles vaccine in terms of cold chain vulnerability?