Hello Fellow COVID-19 Vaccine Providers,

The Michigan Department of Health and Human Services (MDHHS), Division of Immunization, is working to provide you, our COVID-19 providers, with information, education, and updates while working with the COVID-19 Vaccination Program. We are attempting to send weekly tip sheets on different subjects to help answer questions you may have. If you have other questions or concerns that we have not covered, please do not hesitate to contact us at checcimms@michigan.gov.  Below is our tip for week #10.

Week #10 Educational Tip:

Storage units and temperature monitoring devices need regular maintenance to ensure proper operation, maintain required temperatures, and extend the life of the equipment. This equipment protects patients from inadvertently receiving compromised vaccine and protects facilities against costs of revaccinating patients or, replacing expensive vaccines, and losing patient confidence.

Every provider should have a reliable digital data logger (DDL) for each vaccine storage unit and a backup if one malfunctions, needs to be sent out for calibration, or if vaccine needs to be transported. Calibration testing should be done every one to two years or according to the manufacturer’s suggested timeline. CDC recommends that a DDL’s current and valid Certificate of Calibration Testing include:

• Model/device name or number
• Serial number
• Date of calibration (report or issue date)
• Confirmation that the instrument passed testing (or instrument in tolerance)
• Recommended uncertainty of +/-0.5°C (+/-1°F) or less

To protect the storage unit’s power supply:

• Plug in only one storage unit per electrical outlet.
• Use a safety-lock plug or an outlet cover to prevent the unit from being unplugged.
• Post “DO NOT UNPLUG” warning signs at outlets and on storage units to alert staff, custodians, electricians, and other workers not to unplug units.
• Label fuses and circuit breakers to alert people not to turn off power to storage units.
• Use caution when using power outlets that can be tripped or switched off and avoid using built-in circuit switches (that may have reset buttons), outlets activated by a wall switch, and multioutlet power strips.

To help keep the storage unit in proper working condition:

• Check the seals of the storage unit door regularly for signs of wear and tear.

• Check door hinges and adjust so that the door opens and closes smoothly and fits squarely against the body of the unit. Leaving the door open can cause the thermostat to respond to warmer room temperatures, and the unit will work harder to maintain the correct temperature inside. The temperature may become very cold in some parts of the unit. Using an open-door alarm and a self-closing door may be helpful.
• Clean unit coils and motor per manufacturer instructions.
• Clean inside of units to discourage bacterial and fungal growth. Cleaning must be done quickly to minimize the risk of the temperature going out of range.
• Defrost manual-defrost freezers when the frost exceeds either 1 cm or per the manufacturer’s suggested limit. Follow the manufacturer’s instructions. While defrosting, store vaccines temporarily in another storage unit that can maintain appropriate freezer temperatures and monitor temperatures with a DDL.
• Digital data loggers (DDL’s) experience “drift” over time that affects accuracy. If calibration testing indicates the device is no longer accurate within +/-0.5°C (+/-1°F), it should be replaced. Adjustments to correct accuracy are not recommended.
• Storage unit temperatures may need to be adjusted over time. Temperature adjustments should only be made by a vaccine coordinator and not during a busy part of the workday when the door is being frequently opened. The coordinator should confirm there is not another issue (e.g., unit unplugged, door left open, broken DDL, etc.) before making any adjustment to the temperature.
• If you believe there could be an issue with the DDL, use the backup DDL to confirm the temperature before making any adjustments.

If a backup generator is used, it should be tested quarterly and serviced annually, and according to the manufacturer’s guidance.

Pinkbook | Vaccine Storage and Handling | Epidemiology of VPDs | CDC
Vaccine Storage and Handling Toolkit-Updated with COVID-19 Vaccine Storage and Handling Information, Addendum April 12, 2022 (cdc.gov)
Michigan VFC Provider Manual

Please contact us if you have any questions or concerns at checcimms@michigan.gov.

Thank-you for helping to keep Michiganders safe from the COVID-19 virus,

Oakland County Health Division, Immunization Action Plan