In the study, which was supported by MSD and led by Rosie Lyle of Bishopton Veterinary Group, 18 farmers placed temperature loggers in the fridge where they normally store vaccines. Temperatures were then monitored between February and April. Throughout this period, 89% of loggers recorded a temperature outside the 2–8°C range at least once, and 43% recorded temperatures outside this range more than 50% of the time.
The authors say that these findings raise potential concerns about vaccine efficacy.
Rosie found that 55% of the loggers recorded a temperature over 8°C, and 39% recorded a temperature below 2°C.
Across all the fridges monitored, the maximum temperature recorded was 12°C and the minimum was -11.5°C.
Rosie said: "This is a surprisingly wide range. Obviously, these findings are concerning for farmers as we know that both too high and too low temperatures can impair vaccine efficacy.
"Live vaccines tend to be particularly sensitive to elevated temperatures, whereas inactivated vaccines are more affected by freezing, especially when the adjuvant contains aluminium salts".
"It’s important for both farmers and vets to be aware of potential concerns about vaccine efficacy, given the possible impact on herd health and the potential for vaccine failure to reduce trust in vaccines and herd health recommendations".
In light of Rosie’s findings, other XLVets practices are now encouraging farmers to take action to improve medicine storage, including using max/min thermometers or temperature loggers to track fridge temperature, as well as taking steps to maximise the efficiency of each fridge.
Susan Goodfellow, Marketing Manager at XLVets, said: "We wouldn’t have known that this is an important issue to highlight to farmers without collecting the information, so Rosie’s study was very valuable.
"In the XLVets community, we support clinical leadership with these kind of projects – we actively collect data and make sure that farmers can benefit from the latest findings. As a group of independent practices working together, we can achieve much more than we could in isolation."
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