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疫苗儲存和溫度監測的終極指南

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全國各地的醫療機構正在努力了解和實施與疫苗儲存和處理相關的疾病控制中心(CDC)指南和建議。這些指南適用於所有處理疫苗的設施。CDC鼓勵提供商盡快實施這些指南。

參與兒童疫苗(VFC)計劃的提供者必須特別注意這些指南,並應諮詢其州或地方免疫計劃,以獲得具體的建議和要求。

疫苗的安全儲存是保護患者免受疾病侵害的重要組成部分。未能正確儲存疫苗可能會導致患者對疫苗計劃失去信心。如果施用的疫苗由於不適當的溫度或不適當的處理而受到損害,則必須重新接種。當疫苗不能使用且必須處理時,這些錯誤也會導致嚴重的經濟損失。

正確存儲疫苗是提供優質患者護理的重要部分。為了保持疫苗的有效性,必須維持疫苗冷鏈。據疾病預防控制中心稱,疫苗冷鍊是一種溫控環境,用於在最佳條件下維持和分發疫苗。它始於製造商,並以疫苗管理站點結束。如果不維持疫苗冷鏈,疫苗將失去效力並變得無效。


疫苗冷鏈


 

疫苗製造商

 

疫苗分發

 

疫苗到達提供者設施

 

疫苗儲存和處理提供者設施

 

疫苗管理

暴露於過熱,過冷和/或光照會導致效力喪失。一旦效力喪失,就無法恢復。疫苗外觀不是疫苗在不適當條件下儲存的可靠指標。

疫苗儲存和處理工具包反映了免疫實踐諮詢委員會(ACIP)建議,疫苗生產商的產品信息和科學研究的疫苗儲存和處理的最佳實踐。

該工具包概述了CDC建議書,這是保護您的疫苗供應所需的最低限度行動,以及CDC最佳實踐,其中概述了加強保護疫苗供應的其他行動,做法和程序。

重要的是,您的設施應具有正確設置,適當維護並根據需要進行維修的適當存儲和監控設備。該設備可以保護患者免於無意中接受受損疫苗和您的設施,以防止重新接種疫苗的患者,更換昂貴的疫苗,並使您的患者對您的實踐失去信心。

冰箱和冷櫃建議

疫苗儲存單位:冰箱和冷凍機建議

有幾種類型的疫苗儲存單元可供使用。專用單元專門用於存儲疫苗。但是,在適當條件下,家庭級單位也是疫苗冷藏的可接受選擇。

CDC建議使用旨在冷藏或冷凍的專用或醫藥級設備。這些單元可以是緊湊型,櫃檯式或大型。專用單位,有時被稱為“藥品級”,專門用於存儲生物製劑,包括疫苗。

這些單位通常有:

  • 基於微處理器的溫度控制,帶數字溫度傳感器(熱電偶,電阻溫度檢測器[RTD]或熱敏電阻)
  • 風扇強制風扇通過強大的風扇或多個冷卻通風口促進均勻溫度和從超出範圍的溫度快速恢復溫度。

為了充分確保疫苗的安全性,設備應包括一個足夠空間的推薦裝置,以滿足您的最大庫存而不會擠壓。

家用級裝置可以替代醫藥級疫苗儲存裝置。顧名思義,這些裝置主要是為家庭設計和銷售的。然而,不建議將這種類型的冷凍室用於儲存疫苗,並且還應該避免冷藏室的其他區域。如果您的設施提供冷凍疫苗,則需要單獨的冷凍室。

2009年NIST的一項研究表明,醫療級單位比家用和商用組合單位更好地保持所需的溫度。典型的家用,單冷凝器,組合單元不能在冰箱和冷凍室中保持適當的儲存溫度。

這些裝置中的大多數在冰箱部分具有冷點和溫度波動,這使得冷藏疫苗處於凍結的風險中。此外,家用組合裝置中的冷凍室已經證明它不能保持冷凍疫苗的正確溫度。

存儲單元放置

存儲單元外部周圍良好的空氣循環很重要。將存儲單元放置在通風良好的房間內,在單元,天花板和任何牆壁之間留出空間。沒有什麼能阻擋馬達室的蓋子。該單元應堅固平整,單元底部高於地板。確保設備門平穩地打開和關閉,並與設備主體完全貼合。如果沒有正確固定,單元門會對維持疫苗儲存單元的適當內部溫度構成風險。研究發現,大多數單元放置在標準室內室溫的區域內效果最佳,通常在20°C至25°C(68°F至77°F)之間。有關放置和間距的其他指導,請查看製造商提供的用戶手冊。

在任何情況下都不要將任何疫苗存放在宿舍式或酒吧式組合式冰箱/冰櫃中。

這些裝置具有單個外門和蒸發器板/冷卻盤管,通常位於製冰機/冷凍室中。即使用於臨時儲存,這些裝置也會產生凍結疫苗的重大風險。(注意:並非所有小型存儲單元都是宿舍式或條形式單元。用於生物製劑的緊湊型專用裝置可用於儲存疫苗。)

存儲單元門

沒有正確密封或不必要地打開的門不僅會影響裝置的溫度,還會使疫苗暴露在光線下,這會降低某些疫苗的效力。考慮使用安全措施確保設備的門保持關閉狀態 - 例如,自動關閉門鉸鏈,門警報器或門鎖。

溫度監測建議

經修訂的2019年疫苗儲存和處理工具包提供了有關溫度監測最佳實踐以及溫度監測設備和校準的詳細建議。

溫度範圍

冰箱應保持2°C至8°C(36°F至46°F)的溫度。冷凍機應保持-50°C至-15°C(-58°F至+ 5°F)的溫度。冰箱或冷凍恆溫器應設置在出廠設定或中點溫度,這將降低溫度偏移的可能性。有關如何操作恆溫器的說明,請參閱用戶手冊。了解疫苗儲存溫度的唯一方法是使用溫度監測裝置測量和監測疫苗。

溫度監控設備(TMD)

每個疫苗儲存單元必須有TMD。準確反映實際疫苗溫度的溫度歷史記錄對於保護疫苗至關重要。投資可靠的設備比替換疫苗浪費更便宜,因為在超出範圍的溫度下存儲會降低效力。

CDC推荐一種稱為“數字數據記錄器”(DDL)的特定類型的TMD。DDL提供最準確的存儲單元溫度信息,包括單元在推薦溫度範圍之外運行多長時間的詳細信息(稱為“溫度偏移”)。與簡單的最小/最大溫度計不同,它只顯示單元中達到的最冷和最溫度的溫度,DDL提供了以預設間隔記錄的所有溫度的詳細信息。此外,一些醫藥級和專用單元內置了連續溫度監控,與獨立DDL相比具有所有相同的優點。

許多DDL使用緩衝溫度探頭,這是測量實際疫苗溫度的最準確方法。通過緩衝探針測量的溫度使疫苗溫度與通過標準溫度計測量的溫度更接近,標準溫度計傾向於僅反映空氣溫度。

來自DDL的溫度數據可以使用特殊軟件下載到計算機或從網站檢索。該軟件或網站還可以允許您設置溫度讀數的頻率。檢查DDL數據對於疫苗可行性至關重要,因此決定獨立軟件或網站程序是否最適合您的設施非常重要。

將數據保存三年,以便分析長期趨勢和/或反復出現的問題。接受公共疫苗的人可能需要根據州法規的要求更長時間地保存記錄。

使用DDL或其他適當的TMD:

  • 每個疫苗儲存單位
  • 每個運輸單元(緊急或非緊急)
  • 至少有一個備用TMD,以防主設備損壞或出現故障。

使用具有以下功能的DDL:

  • 可拆卸的探頭,最能反映疫苗的溫度(例如,用乙二醇,玻璃珠,沙子或Teflon®緩衝的探頭)
    • 如果可以對整個裝置的溫度監控系統進行校準測試,則可以接受永久嵌入緩衝器中的探頭。
  • 報警超出範圍的溫度
  • 低電量指示燈
    • 由於這些設備通常由電池供電,因此可以隨時提供額外的電池。
    • 顯示當前,最小和最大溫度
  • 建議的不確定度為+/- 0.5°C(+/- 1°F)
  • 記錄間隔(或讀取速率),用戶可編程至少每30分鐘測量和記錄溫度
  • 使用具有當前有效校準測試證書的DDL

校準測試證書

進行校準測試以確保溫度監測設備讀數的準確性符合國家認可的標準。DDL的校準測試證書應包括:

  • 型號/設備名稱或編號
  • 序列號
  • 校準日期(報告或發布日期)
  • 確認儀器通過測試(或儀器處於公差範圍內)
  • 建議的不確定度為+/- 0.5°C(+/- 1°F)或更低

要確定適當的實體是否頒發了校準測試證書或校準報告,請檢查證書是否表明有關校準測試的以下一項或多項:

  • 符合國際標準化組織(ISO)/國際電工委員會(IEC)17025國際標準測試和可追溯性標準
  • 由國際實驗室認可合作組織(ILAC)相互認可協議(MRA)簽字機構認可的實驗室進行
  • 可追溯到美國國家標準與技術研究院(NIST)維護的標準
  • 符合美國材料與試驗協會(ASTM)標準E2877公差等級F或更高等級的規範和測試要求
  • 指另一種可接受的精度驗證方法,例如與其他可追溯參考標準的比較或在測溫固定點的測試

校準測試應每隔一到兩年進行一次,或根據製造商建議的時間表進行。TMD可能會隨著時間的推移而經歷“漂移”,從而影響其準確性。該測試確保設備的準確性繼續符合國家認可的標準。

錯誤處理TMD會影響其準確性。如果TMD掉落,撞到存儲單元的側面,或者可能以任何方式損壞,則應根據另一個校準的TMD檢查其準確性。如果對準確性有任何疑問,應更換或發送設備進行校準測試。

監測疫苗溫度和疫苗設備

監測疫苗儲存設備和溫度是每日責任,以確保您的疫苗供應和您的患者的生存能力。實施常規監測活動可以幫助您快速識別溫度偏移,並立即採取措施糾正它們,防止疫苗流失和患者再次接種的可能性。

某些類型的TMD具有顯著的局限性,不應用於測量疫苗儲存單元的溫度。

這些設備可能難以讀取,因為它們僅在檢查時顯示溫度。這些設備可能無法檢測到超出建議範圍的溫度。CDC不建議使用以下TMD:

  • 酒精或水銀溫度計(即使放在充滿液體的生物垃圾中)
  • 液體瓶雙金屬桿TMDs
  • TMD用於食品
  • 圖表記錄器
  • 紅外TMD
  • 沒有當前有效校準測試證書的TMD

請注意:在硬件和設備商店出售的某些設備旨在監控家庭食物儲存的溫度。它們未經校準且不夠精確,無法確保疫苗儲存在正確的溫度範圍內。使用這些裝置可能會造成損害疫苗的重大風險。

如何處理溫度偏移

任何疫苗的溫度偏移或不適當的儲存條件都需要立即採取行動。製造商包裝插頁中推薦範圍之外的任何溫度讀數都被認為是溫度偏移。一般而言,製造商分析有關溫度偏移幅度和溫度超出範圍的總時間的信息,以及有關疫苗的信息,以確定疫苗是否仍然可行(CDC) 。

如果出現溫度偏移,CDC建議採取以下步驟:

任何聽到警報或註意到DDL溫度漂移的工作人員應立即通知主要或備用疫苗協調員或將問題報告給其主管。

通過標記暴露的疫苗,“不要使用”,並將它們放在與其他疫苗不同的單獨容器中來通知工作人員(不要丟棄這些疫苗)。

疫苗協調員,主管或必要時報告問題的人員應開始使用以下信息記錄事件:

  • 溫度漂移的日期和時間
  • 存儲單元溫度和室溫(如果有)(包括活動期間的最低/最高溫度,如果有的話)
  • 完成報告的人員姓名和事件描述
  • 發生了什麼的一般描述
  • 如果使用DDL,疫苗的時間長度可能會受到影響
  • 受影響疫苗的清單
  • 除疫苗外的單位(包括水瓶)中的物品清單
  • 活動前存儲單元和/或受影響疫苗的任何問題
  • 其他相關信息

實施您的設施SOP,將單位溫度調整到適當的範圍。至少檢查TMD以確保其適當放置在疫苗的中心。

根據您的SOP聯繫您所在州或當地的免疫計劃和/或疫苗製造商,以獲得有關是否使用受影響疫苗的進一步指導,以及有關是否需要召回患者再次接種疫苗的信息。準備提供事件的文檔(例如,溫度記錄數據),以確保您獲得最佳指導。

完成您的活動文檔,包括:

  • 採取的行動
  • 你用疫苗做了什麼以及採取行動需要多長時間
  • 您聯繫的人和收到的指示
  • 你做了什麼來防止類似的未來事件
  • 結果
  • 受影響疫苗的最終處置(例如,縮短每個製造商的失效日期,丟棄或退回)
  • 其他的建議

免疫行動聯盟已開發出溫度監測記錄和疫苗儲存故障記錄記錄,以支持這些活動。

疫苗製造商對事件的響應取決於提供者向製造商提供的信息。如果向同一製造商提供關於同一事件的不同信息,這可能導致關於是否可以使用疫苗或患者是否需要再接種的不同建議。此外,每個事件都是唯一的,基於現有穩定性數據的製造商建議不能應用於可能看似相似的未來事件。

疫苗儲存裝置的日常維護和故障排除

對疫苗儲存裝置進行定期維護對於保持其運行並延長其使用壽命至關重要。CDC疫苗儲存和處理工具包為如何正確維護疫苗儲存單元提供了很好的建議。該工具包還提供有關如何解決設備問題和處理警報的說明。

定期維護疫苗儲存裝置和溫度監測裝置

存儲單元和TMD需要定期維護以確保正常運行。

切勿讓疫苗長時間停留在故障單元中。如果您認為您的設備出現故障,請執行您的緊急SOP。

對所有疫苗儲存裝置和相關設備進行日常維護,使您的設備以最高效率運行。

  • 檢查密封件和門鉸鏈。
  • 按製造商的說明清潔線圈和其他組件。
  • 除霜手動除霜冰櫃。
  • 清潔每個單元的內部,以防止細菌和真菌生長。快速做到盡量減少溫度漂移的風險。
  • 每季度測試一次備用發電機並每年進行一次維修。

解決設備問題

調整存儲單元溫度

存儲單元溫度可能需要隨時間調整。在某些情況下,夏季和冬季可能需要重置恆溫器,具體取決於室溫。

溫度調整應:

  • 由主要或備用疫苗協調員根據TMD和溫度監測日誌的信息製作。
  • 在單獨的門經常打開和關閉的繁忙工作日期間完成。

請記住,即使正常使用,任何存儲單元內的溫度也會略有不同。因此,在進行任何調整之前:

  • 確認設備已牢固插入電源。
  • 檢查存儲單元內的溫度。

等待30分鐘,不要打開門,讓溫度穩定,然後再次檢查,以確定是否應調節溫控器。

如果您認為TMD可能存在問題,請使用備份設備確認溫度。如果您確認需要進行調整:

  1. 有關詳細說明,請參閱用戶手冊。
  2. 如果使用家用設備,請通過緩慢旋轉溫控器旋鈕對溫度較低或較冷的設置進行小幅調整,以避免超出正確的溫度範圍。如果您使用的是醫藥級設備,您可以使用溫度控制器設置精確的溫度。
  3. 調整完成後,讓設備內的溫度穩定30分鐘而不打開門。
  4. 重新檢查溫度。
  5. 根據需要重複這些步驟,直到溫度穩定在冰箱的5°C(40°F)左右或冰箱的-50°C到-15°C(-58°F和+ 5°F)之間。
  6. 考慮在設備中放置額外的水瓶,以幫助提高溫度穩定性

不要將疫苗留在不能保持溫度在建議範圍內的儲存單元中。如果您無法將設備內的溫度穩定在所需範圍內,或者設備中的溫度始終處於該範圍的極高或極端,則您的疫苗供應風險很高。使用您的SOP識別具有適當溫度和足夠存儲空間的替代裝置,直到可以修復或更換主裝置。

如果您使用的是組合儲存裝置,請注意,調節冷凍室溫度會對冷藏室溫度產生不利影響,可能導致冰箱中的冷凍疫苗。

重複警報警報

如果溫度警報反復出現,請在確定並解決原因之前不要斷開警報。對設備門,電源和恆溫器設置進行基本檢查。如果警報繼續觸發或溫度超出範圍,請按照SOP的指示將疫苗轉移到備用裝置。維修技師應檢查您的設備,以確定是否需要維修或更換。

結論

安全有效的疫苗儲存是保護人口免受破壞性疾病的重要組成部分。供應商正在尋找CDC疫苗儲存和處理工具包,以獲取有關疫苗正確儲存,處理,監測和管理的基本信息。與不適當的疫苗儲存相關的風險太深刻,無法忽視。在Helmer Scientific,我們一直致力於設計和製造可靠的專用冰箱和冰櫃超過15年。有關選擇合適設備以幫助滿足CDC建議的更多信息,請訪問www.helmerinc.com

本文中提供的所有信息均直接來自CDC疫苗儲存和處理工具包。有關疫苗儲存和處理的具體指導,請諮詢您所在州和當地的計劃。

Refrigerator and Freezer Recommendations

Vaccine Storage Units: Refrigerator and Freezer Recommendations

There are several types of vaccine storage units available. Purpose-built units are specifically designed to store vaccines. However, household-grade units are also an acceptable option for vaccine refrigeration under the right conditions.

CDC recommends the use of purpose-built or pharmaceutical-grade units designed to either refrigerate or freeze. These units can be compact, under-the-counter style or large. Purpose-built units, sometimes referred to as “pharmaceutical grade,” are designed specifically for storage of biologics, including vaccines.

These units often have:

  • Microprocessor-based temperature control with a digital temperature sensor (thermocouple, resistance temperature detector [RTD], or thermistor)
  • Fan-forced air circulation with powerful fans or multiple cool air vents promoting uniform temperature and fast temperature recovery from an out-of-range temperature.

To fully ensure the safety of vaccines, equipment should include a recommended unit with enough space to accommodate your maximum inventory without crowding.

Household-grade units can be an acceptable alternative to pharmaceutical-grade vaccine storage units. As the name implies, these units are primarily designed and marketed for home use. However, the freezer compartment of this type of unit is not recommended to store vaccines and there may be other areas of the refrigerated compartment that should be avoided as well. If your facility provides frozen vaccine, a separate freezer unit is necessary.

A 2009 NIST study demonstrated that medical-grade units maintain required temperatures better than household and commercial combination units. Typical household, single-condenser, combination units are not capable of maintaining proper storage temperatures in the refrigerator and freezer compartments.

Most of these units have cold spots and temperature fluctuations in the refrigerator portion, which puts refrigerated vaccines at risk of freezing. Moreover, the freezer compartment in a household combination unit has proven it is not capable of maintaining the correct temperature for frozen vaccines.

Storage Unit Placement

Good air circulation around the outside of the storage unit is important. Place a storage unit in a well-ventilated room, leaving space between the unit, ceiling, and any wall. Nothing should block the cover of the motor compartment. The unit should be firm and level, with the bottom of the unit above the floor. Make sure the unit door opens and closes smoothly and fits squarely against the body of the unit. If not secured properly, unit doors pose a risk to maintaining appropriate internal temperatures of vaccine storage units. Studies find most units work best when placed in an area with standard indoor room temperatures, usually between 20° C and 25° C (68° F and 77° F). Check the manufacturer-supplied owner’s manual for additional guidance on placement and spacing.

Do not store any vaccine in a dormitory-style or bar-style combined refrigerator/freezer unit under any circumstances.

These units have a single exterior door and an evaporator plate/cooling coil, usually located in an icemaker/freezer compartment. These units pose a significant risk of freezing vaccines, even when used for temporary storage. (Note: Not all small storage units are dormitory- or bar-style units. Compact, purpose-built units for biologics can be used to store vaccines.)

Storage Unit Doors

A door that is not sealed properly or left open unnecessarily not only affects the temperature in a unit, it also exposes vaccines to light, which can reduce potency of some vaccines. Consider using safeguards to ensure the doors of the unit remain closed—for example, self-closing door hinges, door alarms, or door locks.

Temperature Monitoring Recommendations

The revised 2019 Vaccine Storage and Handling Toolkit provides detailed recommendations around temperature monitoring best practices as well as temperature monitoring devices and calibration.

Temperature Ranges

Refrigerators should maintain temperatures between 2° C and 8° C (36° F and 46° F). Freezers should maintain temperatures between -50° C and -15° C (-58° F and +5° F). Refrigerator or freezer thermostats should be set at the factory-set or midpoint temperature, which will decrease the likelihood of temperature excursions. Consult the owner’s manual for instructions on how to operate the thermostat. The only way to know the temperature where vaccines are stored is to measure and monitor it with a temperature monitoring device.

Temperature Monitoring Devices (TMDs)

Every vaccine storage unit must have a TMD. An accurate temperature history that reflects actual vaccine temperatures is critical for protecting your vaccines. Investing in a reliable device is less expensive than replacing vaccines wasted due to the loss of potency that comes from storage at out-of-range temperatures.

CDC recommends a specific type of TMD called a “digital data logger” (DDL). A DDL provides the most accurate storage unit temperature information, including details on how long a unit has been operating outside the recommended temperature range (referred to as a “temperature excursion”). Unlike a simple minimum/maximum thermometer, which only shows the coldest and warmest temperatures reached in a unit, a DDL provides detailed information on all temperatures recorded at preset intervals. In addition, some pharmaceutical-grade and purpose-built units have built in continuous temperature monitoring which provide all of the same benefits as a standalone DDL.

Many DDLs use a buffered temperature probe, which is the most accurate way to measure actual vaccine temperatures. Temperatures measured by a buffered probe match vaccine temperatures more closely than those measured by standard thermometers, which tend to reflect only air temperature.

Temperature data from a DDL can either be downloaded to a computer using special software or retrieved from a website. The software or website may also allow you to set the frequency of temperature readings. Reviewing DDL data is critical for vaccine viability, so it is important to decide whether independent software or a website program works best for your facility.

Keep the data for three years so it can be analyzed for long-term trends and/or recurring problems. Those receiving public vaccine may need to keep records longer as required by state regulations.

Use a DDL or other appropriate TMD for:

  • Each vaccine storage unit
  • Each transport unit (emergency or non-emergency)
  • Have at least one backup TMD in case a primary device breaks or malfunctions.

Use DDLs with the following features:

  • Detachable probe that best reflects vaccine temperatures (e.g., a probe buffered with glycol, glass beads, sand, or Teflon®)
    • Probes that are permanently embedded in a buffer are acceptable if the temperature monitoring system for the entire unit can be calibration-tested.
  • Alarm for out-of-range temperatures
  • Low-battery indicator
    • Since these devices are typically battery-operated, have a supply of extra batteries on hand.
    • Current, minimum, and maximum temperature display
  • Recommended uncertainty of +/-0 .5° C (+/-1° F)
  • Logging interval (or reading rate) that can be programmed by the user to measure and record temperatures at least every 30 minutes
  • Use DDLs with a current and valid Certificate of Calibration Testing

Certificate of Calibration Testing

Calibration testing is done to ensure the accuracy of a temperature monitoring device’s readings against nationally accepted standards. A DDL’s Certificate of Calibration Testing should include:

  • Model/device name or number
  • Serial number
  • Date of calibration (report or issue date)
  • Confirmation that the instrument passed testing (or instrument is in tolerance)
  • Recommended uncertainty of +/-0 .5° C (+/-1° F) or less

To determine if a Certificate of Calibration Testing or Report of Calibration was issued by an appropriate entity, check to see if the certificate indicates one or more of the following items about calibration testing:

  • Conforms to International Organization for Standardization (ISO)/International Electrotechnical Commission (IEC) 17025 international standards for calibration testing and traceability
  • Performed by a laboratory accredited by International Laboratory Accreditation Cooperation (ILAC) Mutual Recognition Arrangement (MRA) signatory body
  • Traceable to the standards maintained by the National Institute of Standards and Technology (NIST)
  • Meets specifications and testing requirements for the American Society for Testing and Materials (ASTM) Standard E2877 Tolerance Class F or higher
  • Refers to another acceptable accuracy validation method, such as comparison to other traceable reference standards or tests at thermometric fixed points

Calibration testing should be done every one to two years or according to the manufacturer’s suggested timeline. TMDs can experience a “drift” over time, affecting their accuracy. This testing ensures the accuracy of the device continues to conform to nationally-accepted standards.

Mishandling a TMD can affect its accuracy. If a TMD is dropped, hit against the side of a storage unit, or is potentially damaged in any way, its accuracy should be checked against another calibrated TMD. If there is any question about accuracy, the device should be replaced or sent for calibration testing.

Monitoring Vaccine Temperature and Vaccine Equipment

Monitoring vaccine storage equipment and temperatures are daily responsibilities to ensure the viability of your vaccine supply and your patients. Implementing routine monitoring activities can help you identify temperature excursions quickly and take immediate action to correct them, preventing loss of vaccines and the potential need for revaccination of patients.

Certain types of TMDs have significant limitations and should not be used to measure temperatures in a vaccine storage unit.

These devices can be difficult to read because they only show the temperature at the exact time they are checked. These devices may fail to detect temperatures outside the recommended range. CDC does not recommend the following TMDs:

  • Alcohol or mercury thermometers (even if placed in a fluid-filled, biosafe)
  • Liquid vial Bimetal stem TMDs
  • TMDs used for food
  • Chart recorders
  • Infrared TMDs
  • TMDs that do not have a current and valid Certificate of Calibration Testing

Please note: Some devices sold in hardware and appliance stores are designed to monitor temperatures for household food storage. They are not calibrated and not accurate enough to ensure vaccines are stored within the correct temperature range. Using these devices can pose a significant risk of damaging vaccines.

How To Handle Temperature Excursions

Temperature excursions or inappropriate storage conditions for any vaccine require immediate action. Any temperature reading outside the recommended ranges in the manufacturers’ package inserts is considered a temperature excursion. In general, manufacturers analyze information about the magnitude of the temperature excursion and the total amount of time that temperatures were out of range, as well as information about the vaccine in question, to determine whether a vaccine is likely to still be viable (CDC).

CDC recommends the following steps in the event of a temperature excursion:

Any staff who hears an alarm or notices a temperature excursion on the DDL should notify the primary or alternate vaccine coordinator immediately or report the problem to their supervisor.

Notify staff by labeling exposed vaccines, "DO NOT USE," and placing them in a separate container apart from other vaccines (do not discard these vaccines).

The vaccine coordinator, supervisor, or if necessary, the person reporting the problem should begin to document the event with the following information:

  • Date and time of the temperature excursion
  • Storage unit temperature as well as room temperature, if available (including minimum/maximum temperatures during the time of the event, if available)
  • Name of the person completing the report and description of the event
  • General description of what happened
  • The length of time vaccine may have been affected, if using a DDL
  • Inventory of affected vaccines
  • List of items in the unit (including water bottles) other than vaccines
  • Any problems with the storage unit and/or affected vaccines before the event
  • Other relevant information

Implement your facility SOPs to adjust unit temperature to the appropriate range. At a minimum, check the TMD to make sure it is appropriately placed in the center of the vaccines.

Contact your state or local immunization program and/or vaccine manufacturer(s) per your SOPs for further guidance on whether to use affected vaccines and for information about whether patients will need to be recalled for revaccination. Be prepared to provide documentation of the event (e.g., temperature log data) to ensure you receive the best guidance.

Complete your documentation of the event, including:

  • Action taken
  • What you did with vaccine and how long it took to act
  • Whom you contacted, and instructions received
  • What you did to prevent a similar future event
  • Results
  • Final disposition of affected vaccines (e.g., shortened expiration date per manufacturer, discarded, or returned)
  • Other comments

The Immunization Action Coalition has developed a Temperature Monitoring Log and a Vaccine Storage Troubleshooting Record to support these activities.

Responses from vaccine manufacturers to events depend on information given by the provider to the manufacturer. If different information about the same event is provided to the same manufacturer, this can lead to different recommendations on whether vaccine can be used or whether patients need to be revaccinated. In addition, each event is unique, and manufacturer recommendations based on existing stability data cannot be applied to future events that may appear to be similar.

Routine Maintenance & Troubleshooting for Vaccine Storage Units

Conducting regular maintenance on your vaccine storage units is essential for keeping them in operation and giving them a long usable life. The CDC Vaccine Storage and Handling Toolkit gives great recommendations on how to properly maintain your vaccine storage units. The toolkit also provides instructions on how to troubleshoot equipment problems and handle alarms.

Regular Maintenance of Vaccine Storage Units and Temperature Monitoring Devices

Storage units and TMDs need regular maintenance to ensure proper operation.

Never allow vaccines to remain in a malfunctioning unit for an extended period. If you believe your unit has failed, implement your emergency SOPs.

Conduct routine maintenance for all vaccine storage units and related equipment so that your equipment functions at maximum efficiency.

  • Check seals and door hinges.
  • Clean coils and other components per manufacturer direction.
  • Defrost manual-defrost freezers.
  • Clean the interior of each unit to discourage bacterial and fungal growth. Do so quickly to minimize the risk of a temperature excursion.
  • Test any backup generator quarterly and have it serviced annually.

Troubleshooting Equipment Problems

Adjusting Storage Unit Temperatures

Storage unit temperatures may need to be adjusted over time. In some situations, thermostats may need to be reset in summer and winter, depending on room temperature.

Temperature adjustments should:

  • Be made by the primary or alternate vaccine coordinator, based on information from the TMD and temperature monitoring log.
  • Be done at a time that is not during a busy workday when the unit door is frequently opened and closed.

Remember that temperatures within any storage unit will vary slightly, even with normal use. Therefore, before making any adjustment:

  • Confirm the unit is securely plugged into a power source.
  • Check the temperature inside the storage unit.

Wait 30 minutes, without opening the door, to allow the temperature to stabilize and then check it again to determine if the thermostat should be adjusted.

If you believe there could be an issue with your TMD, use your backup device to confirm the temperature. If you confirm that an adjustment is needed:

  1. Refer to the owner’s manual for detailed instructions.
  2. If using a household unit, make a small adjustment toward a warmer or colder setting by turning the thermostat knob slowly to avoid going outside the correct temperature range. If you are using a pharmaceutical grade unit, you will be able to set a precise temperature using the temperature controller.
  3. Once the adjustment is made, allow the temperature inside the unit to stabilize for 30 minutes without opening the door.
  4. Recheck the temperature.
  5. Repeat these steps as needed until the temperature has stabilized at around 5° C (40° F) for a refrigerator or between -50° C and -15° C (-58° F and +5° F) for a freezer.
  6. Consider placing additional water bottles in the unit to help improve temperature stability

Do not leave vaccines in a storage unit that does not maintain temperatures within the recommended range. If you are unable to stabilize the temperature in your unit within the required range, or temperatures in the unit are consistently at the extreme high or low end of the range, your vaccine supply is at high risk. Use your SOPs to identify an alternative unit with appropriate temperatures and enough storage space until the primary unit can be repaired or replaced.

If you are using a combination storage unit, note that adjustments to the freezer temperature can adversely affect the refrigerator compartment temperature, possibly resulting in frozen vaccines in the refrigerator.

Repeated Alarm Alerts

If the temperature alarm goes off repeatedly, do not disconnect the alarm until you have determined and addressed the cause. Do basic checks of the unit door, power supply, and thermostat settings. If the alarm continues to trigger or the temperature remains out of range, transfer vaccines to a backup unit as directed by your SOPs. A repair technician should check your equipment to determine the need for repair or replacement.

Conclusion

Safe and effective vaccine storage is an essential part of protecting the population from devastating disease. Providers are looking to the CDC Vaccine Storage and Handling Toolkit for essential information on proper storage, handling, monitoring, and administration of vaccines. The risks related to improper vaccine storage are too profound to ignore. At Helmer Scientific, we have been designing and manufacturing reliable, purpose-built refrigerators and freezers for over 15 years. For more information on choosing the right equipment to help meet CDC recommendations, please visit www.helmerinc.com.

All the information provided in this post is directly from the CDC Vaccine Storage and Handling Toolkit. Please consult with your state and local programs for specific direction regarding vaccine storage and handling.