Have purpose-built vaccine refrigerators reduced the cost of vaccine losses in South Australia?

Objectives: There is limited epidemiological data on the performance of different refrigerator types for vaccine storage in the real world. This study aims to measure if the introduction of purpose-built vaccine refrigerators has reduced the cost of vaccine losses in South Australia.

Methods: Data were taken from a register for all recorded vaccine storage cold chain events in South Australia from 2008 to 2009 and a survey of vaccine providers conducted in 2009.

Results: There were 531 respondents to the survey (51% response rate). A greater proportion of cold chain breaches in purpose-built vaccine refrigerators did not lead to a loss of vaccine (10.3%) compared with the other refrigerator types. Purpose-built vaccine refrigerators had a relative risk of 3.31 (95% CI, 2.15-5.11) of a heat event (as opposed to cold event) and were more likely to have a cold chain breach from electrical failure (relative risk ratio 15.05, 95% CI 4.04-56.05) than bar refrigerators. The average cost of loss of vaccine for purpose-built vaccine refrigerators was $2,321.20, which was greater than the cost of vaccine loss from a bar refrigerator of $1,339.06 (95% CI $61.47-1,902.82).

Conclusions: Although purpose-built vaccine refrigerators were less likely to lead to vaccine loss per cold chain breach, they had a greater average cost of vaccine loss per cold chain event because they held a greater volume of vaccine. There is a need for development of Standards to guide purpose-built vaccine refrigerators manufacturing and a review of the National Vaccine Storage Guidelines to place a greater emphasis on the need for back up plans in the event of electrical failure.