- Most refrigerated veterinary vaccines are kept between 2 and 8°C without freezing, and the manufacturer, distributor and veterinary team share responsibility for holding that range up to the moment of administration.
- After any temperature excursion, mark the product "Do not use" and return it to correct storage, then consult the manufacturer before releasing or discarding it.
- A fridge returning to temperature does not prove a vaccine is still effective, appearance is not enough to judge, and the decision rests on exposure data and product instructions.
This article is for professional education; each decision should be made with the responsible veterinarian and in line with the product's instructions and the manufacturer's advice.
What is the correct storage range for veterinary vaccines?
The 2022 AAHA Canine Vaccination Guidelines state that refrigerated vaccines should be kept between 2 and 8°C, with the thermostat set mid-range at about 5°C. [2] USDA APHIS gives the same range for refrigerated vaccines, notes that some vaccines must be frozen at -15°C or below, and stresses that refrigerated vaccines should never be frozen or put through freeze–thaw cycles. [3]
The final reference for each product is its label and package insert as approved by the registering authority in your country. AAHA emphasises that the cold chain runs from the manufacturer to the moment of administration, that the manufacturer, distributor and veterinary team share responsibility for it, and that a written standard operating procedure for ordering, storage and administration is essential. [2]
How should the vaccine fridge be set up before anything goes wrong?
Most excursions are found late because the fridge was never set up to be monitored. AAHA recommends a unit used for vaccines only, either purpose-built or a stand-alone household fridge, with vaccines stored centrally about 2 to 3 inches (roughly 5 to 7.5 cm) from the walls and door for airflow, and no use of salad or fruit drawers, where temperatures are unstable. [2]
AAEP adds the monitoring elements:
- A working thermometer in the fridge, with temperatures checked twice daily and logged, especially when several people share the task. [1]
- A vaccine storage alarm, which warns before the threshold that would force products to be discarded. [1]
- An up-to-date inventory log with vaccine name, manufacturer, lot number, expiry date, doses received and condition on arrival, earliest-expiring stock used first, and one person responsible for receiving and storage. [1]
USDA APHIS recommends a calibrated thermometer with temperatures recorded at least daily, suggests placing the probe in a container of simulated vaccine for a truer reading, and advises inspecting shipments and their cold chain monitors on arrival. [3]
How do you receive a vaccine delivery without inheriting someone else’s problem?
Many excursions happen before the vaccine reaches your fridge, during shipping or because of unsuitable packaging. [1] Treat receipt as a checkpoint rather than a signature. USDA APHIS recommends inspecting shipments on arrival, including cold chain monitors, to detect any out-of-range exposure in transit, and writing the packing time on the outer package so that transit time is known on arrival. [3]
The same document explains the limits of indicators: heat indicators flag exposure above 50°F (10°C) and record its duration for up to 48 hours, while freeze indicators flag exposure below 32°F (0°C) without showing how long it lasted. [3] On receipt, record the condition of the delivery in the inventory log alongside batch, expiry and number of doses, [1] and if an excursion shows up, do not put the vaccines with sound stock: quarantine and label them and contact the supplier before accepting them.
What should you do during a power cut?
Keep the doors shut. AAEP notes that a kitchen-sized fridge (20 to 24 cubic feet) can hold its temperature for 6 to 9 hours if the doors stay closed, and that if the outage will last longer, vaccines should be moved to a container kept cold with ice and its temperature monitored. [1] That is a guide figure for one type of fridge; it does not replace knowing how your own unit performs in a hot environment.
When power returns, check the fridge temperature at once to see whether the vaccines were affected. [1] If you have no record of the highest temperature reached and for how long, record that gap explicitly rather than assuming nothing happened.
What are the steps after a temperature excursion?
- 1Quarantine and label"Do not use", stop dispensing
- 2Restore storageBack to correct conditions
- 3Exposure dataDuration, highest and lowest reading
- 4ManufacturerShare data, request advice
- 5Documented decisionRelease or discard, with approval
- 6Root causeFix the alarm or procedure
In its handout for emergency vaccination campaigns, USDA APHIS advises marking suspect vaccine “Do not use”, returning it to proper storage and not discarding it before seeking direction from those in charge. [3] The same principle works in a clinic: neither use nor discard until a decision is made. AAEP advises consulting the manufacturer if a vaccine has been exposed to temperatures outside the recommended range or has changed colour in storage. [1]
Keep two steps apart: returning the product to suitable storage, an immediate action that protects it from further harm, and deciding whether it can be used, which the responsible veterinarian makes after hearing from the manufacturer. So prepare before you call: product name, batch and expiry, when the excursion started and ended, the highest or lowest temperature recorded, and storage conditions before and after the event.
| Situation | First action | Who decides on use |
|---|---|---|
| Long outage expected | Move vaccines to a monitored cold container | No decision if range held |
| Power restored after outage | Check temperature and log at once | Vet after reviewing data |
| Reading out of range | Label, quarantine, restore storage | Vet after manufacturer advice |
| Frozen or colour change | Withdraw from use | Vet after manufacturer advice |
How do you protect vaccines on field visits and in extreme heat?
In hot climates the weakest link is often outside the clinic: handover, loading the vehicle and waiting on site. AAEP warns that a freezer pack in a cooler is not sufficient to hold the range through a working day, that vaccines should not sit directly on ice packs but be separated by paper or bubble wrap, and that the cooler needs a thermometer checked every time it is opened. [1]
USDA APHIS recommends insulated containers, an insulating layer between coolant packs and vaccines to prevent accidental freezing, a thermometer placed beside the vaccines rather than touching the packs, carrying the cooler in the passenger compartment rather than the boot, and keeping the number of transfers to a minimum. [3] AAHA adds that vaccines should stay in their closed packaging until use, as delays in reconstitution or administration can reduce efficacy. [2]
Hypothetical example
Power returns to a veterinary clinic in the morning after an overnight cut. The fridge has only a display showing the current temperature, which is within range. The coordinator does not treat that as proof of safety: every vaccine is labelled “Do not use” and kept refrigerated, the building manager is asked for the outage start and end times, and the data and batch numbers are sent to the manufacturers.
After the replies, the responsible vet releases some products and discards others, recording the decision for each batch. The clinic then adds a min/max recording thermometer, an alarm that reaches the on-call phone out of hours, and a named deputy for when the main person is away.
How do you test the team’s readiness?
Name a lead and a deputy, and write a short procedure for fridge or alarm failure to post next to the unit. Because AAHA treats the cold chain as a shared responsibility that includes the veterinary team, [2] everyone who receives, dispenses or transports vaccines should know the procedure. Rehearse it periodically: who spots the problem, who labels, who calls the manufacturer, and where vaccines go if the outage drags on.
Conclusion
Set the fridge up for monitoring before an incident, and after any excursion quarantine and label the product and return it to correct storage, then gather the exposure data and consult the manufacturer. The decision to release or discard rests with the responsible vet and is recorded for each batch.
Frequently asked questions
If the fridge is back in range, is the vaccine still usable?
Not necessarily. Restoring temperature only protects the product from further harm. Usability depends on how long and how far it was out of range and on the manufacturer's view. [1, 3]
Is checking the vial's appearance enough?
No. AAEP advises consulting the manufacturer if a vaccine has been outside the recommended range or has changed colour; the absence of visible change does not prove potency. [1]
What is the correct storage range for refrigerated vaccines?
AAHA guidance gives 2 to 8°C with the thermostat set at about 5°C, but the final reference for each product is its label and package insert. [2]
What if part of the batch was used before the excursion was found?
Escalate immediately to the responsible veterinarian, use the records to identify animals that received doses from the affected batch, and wait for the manufacturer's advice on any follow-up.
Is a cool box with an ice pack enough for field visits?
AAEP warns that a freezer pack in a cooler is not sufficient to hold the range through a working day and recommends a thermometer inside the cooler, checked each time it is opened. [1]
References
- American Association of Equine Practitioners (AAEP). Vaccine Storage and Handling
- American Animal Hospital Association (AAHA). 2022 AAHA Canine Vaccination Guidelines: Vaccine Storage and Handling (2022)
- USDA APHIS; Center for Food Security and Public Health, Iowa State University. Vaccination for Contagious Diseases: Handling & Transportation (FAD PReP/NAHEMS) (2014)
