Vaccines — Types and Cold Chain

A 32-year-old woman attends the immunization clinic for routine vaccination. The nurse informs you that the vaccine vial of inactivated polio vaccine (IPV) was inadvertently left on the shelf at room temperature (25°C) for 6 hours yesterday. The vial is still within its expiry date. What is the most appropriate next step?

During a vaccination drive in a rural health centre in Madhya Pradesh, you discover that the oral polio vaccine (OPV) vials stored in the vaccine refrigerator have been kept at 4°C instead of the recommended 2–8°C range. The temperature log shows the refrigerator has been running at 4°C for the past 3 days. The vials are still within expiry and show no visible discoloration. What is your most appropriate immediate action?

Which of the following vaccines requires the most stringent cold chain maintenance at +2°C to +8°C and is most sensitive to freezing?

A 6-month-old male infant from Delhi is brought to the immunization clinic for his routine vaccination. The health worker notes that the vaccine vial of pentavalent (DPT-HepB-Hib) was opened 4 hours ago at room temperature (28°C) and has been stored on the shelf without a vaccine vial monitor (VVM). The vial has no visible cracks or contamination. The health worker is unsure whether the vaccine can still be used. According to WHO and Indian immunization guidelines, what is the most appropriate action?

Regarding vaccine types and their characteristics, all of the following statements are correct EXCEPT: