How to Calculate Vaccine Storage Requirements
According to the Centers for Disease Control and Prevention (CDC) the timing of the flu season can vary but most commonly peaks in the U.S. in January or February. However, seasonal flu activity can begin as early as October and continue to occur as late as May.
Healthcare facilities should be preparing for the 2013-14 flu season by first making certain that they have the required number of doses on hand and the proper refrigeration equipment for vaccine storage. This post will take a look at both issues.
How to Calculate Vaccine Doses
Calculating vaccine doses you will need for a flu season is based, logically, on the number you typically administer during a flu season. In all likelihood you may use more refrigerated vaccine than frozen vaccine.
In making your calculations keep in mind that the CDC suggest maintaining a 60-day supply but ordering replacement stock (if needed) on a 30-day cycle. Another calculation is enough space to hold the year’s largest inventory, typically before the start of the school year or flu season. The reordering cycle is why it is a good practice to count your stock on a monthly basis taking note of expiration dates. Expired vaccines should not be used, but instead disposed of in a proper manner.
How to Determine Refrigeration Capacity
Once you’ve calculated your vaccine storage needs you can select the size of the pharmaceutical-grade refrigerator and/or freezer needed. The following tables provide a guideline.
| Maximum doses of refrigerated vaccines | Minimum cubic feet required |
| 1000-2000 | 40 |
| 900-1000 | 36 |
| 801-900 | 21-23 |
| 701-800 | 17-19.5 |
| 400-700 | 16.7 |
| 100-399 | 4.9-6.1 |
| Maximum doses of frozen vaccine | Minimum cubic feet required |
| 501-6000 | 7-14.8 |
| 201-500 | 5-5.6 |
| 0-200 | 3.5-4.9 |
Specifying Vaccine Refrigeration Equipment
Residential or commercial-grade refrigerators and freezers should not be used for vaccine storage. Such equipment is incapable of maintaining the exacting temperature control needed to prevent loss of vaccine potency, which is estimated at a loss of $20 million per year due to poor refrigeration. It’s not only a financial loss. Ineffective inoculations cause inconveniences for patients who have to return to be re-vaccinated, and for healthcare personnel who could be spending this time with other patients.
The CDC suggests thinking of your cold storage equipment as insurance against loss of vaccine potency by providing exacting temperature control.
Recommended Storage Temperatures and Storage Procedures
Vaccine manufacturers designate proper storage temperatures for their formulations but in general most refrigerated vaccines must be stored between 2° and 8°C and frozen vaccines between -50° and -15°C. Check temperatures when shipments are received to be certain that they have not been compromised and immediately place the products in vaccine refrigerators or freezers. It is a good practice to:
- Keep contents in their original packages
- Store with early expiration dates toward the front of the unit
- Enable air to circulate between contents
- Allow 2-3 inches of space between contents and the walls and back of the unit
- Fill unused space (and on-door shelves or bins) with cold water bottles or freezer packs to help stabilize internal temperatures
For additional details see our post on CDC Vaccine Storage Compliance then contact the vaccine refrigeration specialists at Tovatech to discuss the equipment you need.
