Vaccine Storage and Handling
Core concepts
Storage and handling questions test the cold chain. Most refrigerated vaccines are stored at 2°C to 8°C (36°F to 46°F); frozen vaccines require a specific freezer range, commonly -50°C to -15°C depending on the product. Know that some vaccines (varicella, MMR in certain forms, zoster) are heat-sensitive and some are freeze-sensitive - freezing a freeze-sensitive vaccine (many adjuvanted or aluminum-containing products) can destroy it permanently.
Understand temperature monitoring: use a calibrated digital data logger with a buffered probe, record minimum and maximum temperatures at least twice daily, and keep logs. Place vaccines away from the walls, floor, and door; do not store food or specimens in a vaccine unit. Rotate stock using first-expiry, first-out.
Traps
Questions often present a temperature excursion and ask what to do. The safe answer: label the affected vaccine "do not use," keep it at proper temperature, and contact the manufacturer or immunization program for guidance - do not discard automatically and do not administer. Another trap is mixing storage ranges between refrigerated and frozen products, or assuming a brief excursion is always harmless.
Worked example / rule of thumb
Rule of thumb: "When in doubt, do not use - quarantine and call." If a logger shows 10°C overnight, do not give those doses; isolate them, document the excursion, and seek manufacturer guidance on whether the product remains viable.