6 Best Practices for Refrigerated Vaccine Storage and Handling

With flu season rapidly approaching, pharmacies will once again be filling their refrigerators full of lifesaving influenza vaccines to add to their already extensive vaccine inventory.

It’s crucial that the cold chain isn’t broken, so the efficacy of those vaccines isn’t put at risk. Unfortunately, a paper published in 2007 in Vaccine estimated that a shocking 14% to 35% of refrigerated vaccines are exposed to freezing at some point,¹ and that doesn’t even encompass all excursions.

In light of this, here are some of the most commonly missed best practices for refrigerated vaccine storage and handling:

1. Selecting a Thermometer

Make sure you’re using a thermometer that will accurately measure the temperature of the vaccine, not the ambient air. For this reason, food thermometers aren’t recommended; plus, they fluctuate rapidly when the door is opened. The probe of the thermometer should be suspended in glycol.

The thermometer should have a Certificate of Traceability, and you should have documentation that it has been calibrated. Also, remember that calibration doesn’t last forever, so be sure to send your thermometer off to be recalibrated before the due date, which is often put on a tag attached to it.^2-3

2. Selecting a Refrigerator

Dorm-style refrigerators can’t be used for medications because they’ve been shown to be too unstable. Think about it: the freezer is inside the refrigerator and blowing air into the refrigerator compartment.

The CDC lists full-size freezer/refrigerators as “not preferred” but “acceptable,” as long as only the refrigerator compartment is used. However, in my experience, they don’t hold temperatures well either, partially because the freezer is still blowing cold air into the refrigerator.

Stand-alone refrigerators or medical refrigerators are best. After all, if you’re going to entrust $10,000 or more of product to your refrigerator, do you really want the cheapest one you can find? After you purchase a refrigerator, it will take several days for the temperatures to stabilize within the required range.^2-4

3. Stabilizing the Temperature

Jugs of water act as a heat reservoir, absorbing excess heat when the door is opened and releasing it as the refrigerator cools off. From my experience, this can reduce the total temperature range a refrigerator is in by several degrees Fahrenheit. It’s also a CDC recommendation.

The jugs should be on the door, on the bottom (if you have salad drawers, remove them and put jugs of water in their place), and on the top. They should be labeled “Do not drink” because food and drink shouldn’t be kept in a vaccine refrigerator. If you actually go with a combination refrigerator/freezer, you have very little room left to store product because of the small size of the refrigerator compartment.³

4. Appropriate Labeling

You need the following labels:

“Do Not Unplug” Sign

This should be placed next to the power outlet.

“Do Not Adjust” Sign

This should be placed next to the temperature adjustment for the refrigerator. Absolutely no one should adjust the temperature without notifying one of the pharmacy’s vaccine coordinators. They can be pharmacists or technicians, but they need to be very familiar with vaccine storage and handling procedures.³

5. Checking Temperatures

The actual process seems to be routinely overlooked^2-3:

· Temperatures should be checked a minimum of twice-daily; however, it’s better to use continuous-read thermometers. There are even thermometers available that can be connected to a tablet or smartphone so the temperature can be monitored remotely. That way, if an excursion occurs, you can quickly recognize it and bring it back within range.

· If you’re using a thermometer that doesn’t have the ability to continuously monitor temperatures, be sure to 1) check the minimum and maximum (this lets you know if you had an excursion since the last time you checked it) and 2) reset the minimum and maximum afterwards so it’s ready for the next time period.

· The probe of the thermometer (as well as the medications) should be placed in the center of the refrigerator, away from the walls, as this is the most stable part of the refrigerator.

6. Handling Out-of-Range Temperatures

I’m always surprised how often temperatures are recorded as out of range and no action is taken, or procedures are even written to “adjust the temperature” and “recheck in 1 (or 2) hour(s).” Remember, if your vaccine hasn’t been stored constantly at the appropriate temperature, the manufacturer can’t necessarily guarantee the product’s viability.

Here is your step-by-step guide for handling this properly:

· As quickly as possible, get the vaccine stored within range. Sometimes, this can mean moving it to another refrigerator.

· Determine the maximum possible time it could’ve been out of range. This is where continuous-read thermometers can save you a lot of money. If you’re only checking the temperatures twice-daily and you find an excursion, it’s likely your maximum possible time out of range will be 12 hours, or close to it. I once called a manufacture for a $3000 refrigerated medication and was told it only had stability data going out 8 hours, so I had to throw it away. That 1 product cost me more than a good refrigerator and continuous read-thermometer combined.

· Record the lot numbers, expiration dates, and manufacturer of everything in the refrigerator.

· Call the manufacturers of those products. Tell them you had an excursion and are looking for any off-label data that your products are still viable. They’ll ask you what the lot number and expiration date is and whether this is the first time the product has been exposed to an excursion. They’ll tell you either 1) they have no data to support the excursion (which means throw it away) or 2) they have stability data to support the excursion. Sometimes, though, they’ll limit the beyond-use date of those products.

· Document everything. For every product you call about, you should get the case number from the manufacturer and document it on the same log you recorded the lot number and expiration date. You should also document who you spoke to and what they told you. This document should be stapled to your temperature log and retained with it for 3 years. The products that have experienced an excursion should be clearly marked on the packaging. That way, if you have another excursion, you can easily identify the product that has already been through one. If any product has short dating due to an excursion, label the new beyond-use date clearly on the package so it’s not accidentally used past that date.^2-3

References

1. Matthias DM, Robertson J, Garrison MM, et. Al. Freezing temperatures in the vaccine cold chain: a systematic literature review. Vaccine. 2007 May 16;25(20):3980-3986.

2. Immunization Action Coalition. Don’t be guilty of these preventable errors in vaccine storage and handling! IAC website. immunize.org/catg.d/p3036.pdf. Updated January 17, 2015. Accessed June 25, 2016.

3. CDC. Vaccine storage and handling toolkit. CDC website. cdc.gov/vaccines/hcp/admin/storage/toolkit/storage-handling-toolkit.pdf. Updated December 16, 2015. Accessed June 25, 2016.

4. National Institute of Standards and Technology. Storage and monitoring of vaccines. NIST website. nist.gov/pml/div685/grp01/vaccines.cfm. Updated May 6, 2016. Accessed June 25, 2016.