Institute for General Practice, University of Duisburg-Essen, University Hospital Essen, Essen, Germany.
Institute of General Practice and Family Medicine, University of Bonn, Bonn, Germany.
PLoS One. 2019 Nov 19;14(11):e0224972. doi: 10.1371/journal.pone.0224972. eCollection 2019.
Protecting vaccines from freeze damage is considered one of the most poorly addressed problems in vaccine management. Freezing may impair the potency especially of adsorbed vaccines. The Keep Cool study aims at ensuring optimal vaccine storage conditions in general practices. This publication analyses the baseline data using standardised temperature recordings.
This prospective study in German general practices analysed 7-day temperature recordings of refrigerators used for vaccine storage. Temperatures were recorded continuously using a standardised data logger with an accuracy of ±0.4 °C. The prevalence rates of refrigerators within the target range (2 to 8 °C) and of those reaching critically low temperatures (≤0 °C) were calculated. In addition, the cumulative time and the duration of single episodes beyond the target range were computed. To assess for structural deficits, the prevalence of refrigerators with a cycling of >5 °C was determined. Generalised linear mixed models were applied to analyse correlating factors between the dependent variables 'within temperature range' and 'reaching critically low temperatures' with practice characteristics.
The study included 64 of 168 practices (38.1% response rate) with 75 refrigerators. The prevalence of refrigerators with temperatures within the target range was 32.0% (n = 24), and 14.7% (n = 11) reached critically low temperatures <0 °C. 44.0% of refrigerators (n = 33) showed temperatures >8 °C and 28.0% (n = 21) <2 °C. Of the 168 hours recorded per refrigerator, the average cumulative time >8 °C was 49 hours, <2 °C 75 hours and ≤0 °C 74 hours. The longest consecutive period of critically low temperatures was 168 hours (mean: 39±53). The prevalence of refrigerators with a cycling range of >5 °C was 29.3%.
Given the importance of immunisation, the results of our study call for action, as two-thirds of the refrigerators exhibited cold chain breaches and 15% reached critically low temperatures threatening vaccine potency.
保护疫苗免受冻结损坏被认为是疫苗管理中最未得到妥善解决的问题之一。冻结可能会损害特别是吸附疫苗的效力。“保持冷藏”研究旨在确保一般实践中的最佳疫苗储存条件。本出版物使用标准化温度记录分析基线数据。
这项在德国一般实践中的前瞻性研究分析了用于储存疫苗的冰箱的 7 天温度记录。使用带有±0.4°C 精度的标准化数据记录器连续记录温度。计算处于目标范围（2 至 8°C）内的冰箱和达到临界低温（≤0°C）的冰箱的流行率。此外，计算超出目标范围的累计时间和单个事件的持续时间。为了评估结构缺陷，确定了循环超过 5°C 的冰箱的流行率。应用广义线性混合模型分析与实践特征相关的因变量“在温度范围内”和“达到临界低温”的相关因素。
该研究包括 168 个实践中的 64 个（38.1%的回复率），有 75 个冰箱。处于目标范围内的冰箱的流行率为 32.0%（n=24），14.7%（n=11）达到临界低温<0°C。44.0%的冰箱（n=33）显示温度>8°C，28.0%（n=21）<2°C。在每个冰箱记录的 168 小时中，>8°C 的累计时间平均为 49 小时，<2°C 为 75 小时，≤0°C 为 74 小时。连续达到临界低温的最长时间为 168 小时（平均：39±53）。循环范围超过 5°C 的冰箱的流行率为 29.3%。
鉴于免疫接种的重要性，我们的研究结果需要采取行动，因为三分之二的冰箱出现冷链破裂，15%达到威胁疫苗效力的临界低温。
