A vaccine that has been frozen or left warm usually looks exactly like a good one. That is the problem. Nobody notices until the clinic has used it, or until a supervisor checks the temperature log and finds a gap.
Most vaccines in routine use need to stay between +2 °C and +8 °C. Some, especially those containing an aluminium adjuvant, are ruined by freezing, and freezing does its damage far faster than heat does. So the goal is not "as cold as possible". It is steady, in the right band, all the time.
Put the fridge in the right place
Keep it out of direct sun and away from the wall by a hand's width so the back can breathe. In Terai districts, a fridge in a tin-roofed store room works much harder in May than it did in January. If you have a choice of rooms, pick the coolest one, not the most convenient one.
Read the thermometer twice a day
Morning and before closing, every day, including Saturdays if someone is on duty. Write the reading down. A log that has been filled in later from memory is worse than no log, because it hides the problem.
If your fridge has a minimum and maximum reading, record those too and reset them. That is how you find out what happened overnight.
Pack it properly
- Keep vaccines in the middle shelves, never touching the walls or the cooling plate.
- Don't store food, drinks or lab samples with the vaccines.
- Leave space between boxes so cold air can move.
- Fill empty space at the bottom with water bottles. They hold the cold during a power cut.
Plan for power cuts
Load-shedding is less common than it was, but outages still happen, especially outside the valley. Before one happens, know:
- How long your fridge holds temperature with the door shut. Ice-lined and Sure Chill type refrigerators can hold for days; an ordinary domestic fridge may manage only a few hours.
- Who decides when to move the stock to cold boxes.
- Where the conditioned ice packs are kept.
The single most useful rule during an outage is simple: keep the door closed.
When you're not sure
If you think a freeze-sensitive vaccine may have frozen, set it aside, label it, and ask your supervisor or the district cold chain officer before using it. The shake test exists for exactly this situation, and they will know whether to run it.
We supply Godrej vaccine refrigerators, lab refrigerators and freezers. If you are replacing an old domestic fridge, ask us about the options and we can suggest a size for your daily stock.