Ryan raises a very important question. WHO PQS believes, but cannot yet give a figure, that the appropriate utilization factor should be different (and lower) in health facility refrigerators. In these settings, easy access to vaccines, storage of diluent, and the need to segregate opened and unopened vials, means that the close packing found in district and higher level refrigerators cannot be achieved with current refrigerator designs. Another major reason is that vaccine cartons frequently contain too many doses for them to be operationally useful in smaller health facilities - this is especially true of cartons containing multi-dose presentations. Consequently HF refrigerators frequently store vaccines and diluents as individual vials and countries adopt ad-hoc solutions by storing them in plastic boxes or trays; the attached photograph (from Anthony Battersby) shows one of these approaches (Kenya). Note also the presence of Oxytocin in a segregated area of this refrigerator (see parallel postings on this topic).
The efficient use of space in HF refrigerators is an outstanding design problem that WHO PQS has identified as part of an on-going review of refrigerator specifications. As part of this review, we need to gather systematic field data on actual usage at sub-national and health facility level; any suggestions on how to do this would be welcome.
Denis