Importance of Maintaining the Cold Chain
Vaccines are sensitive biological products which may become less effective, or even destroyed, when exposed to temperatures outside the recommended range. Cold-sensitive vaccines experience an immediate loss of potency following freezing. Vaccines exposed to temperatures above the recommended temperature range experience some loss of potency with each episode of exposure. Repetitive exposure to heat episodes results in a cumulative loss of potency that is not reversible. However, information on vaccine degradation is sparse and multipoint stability studies on vaccines are difficult to perform.
Cold Chain at EPI
The Expanded Program on Immunization, Pakistan ensures that an effective product is being used as Vaccine failures caused by administration of compromised vaccine may result in the re-emergence or occurrence of vaccine preventable disease. Therefore careful management of resources is followed religiously as these Vaccines are expensive and can be in short supply. Loss of vaccines may result in the cancellation of immunization clinics resulting in lost opportunities to immunize. Another fundamental of maintaining the potency of vaccines is as revaccination of people who have received an ineffective vaccine is professionally uncomfortable and may cause a loss of public confidence in vaccines and/or the health care system.
EPI owns with pride an Effective Cold Chain by combining the following three main elements to ensure proper vaccine transport, storage, and handling.
- Trained personnel
- Transport and storage equipment
- Efficient management procedures
Additionaly the following protocols are followed in the program: -
- All immunization providers are responsible for ensuring the vaccines they administer have been correctly stored.
- All immunization providers storing vaccines must use a pharmaceutical refrigerator.
- All immunization providers must have an electronic temperature recording device.
- Each immunization providers must have a written cold chain management policy and allocate overall responsibility for cold chain management (including temperature monitoring) to a designated person(s).
- Immunization providers/clinics should review and update their cold chain management policy on need basis.
- The vaccine refrigerator temperatures must be monitored and recorded on a daily basis. The data loggers should be reviewed in accordance with the National Guidelines for Vaccine Storage and Distribution.