[Cold chain maintenance in vaccines: a systematic review]

Systematic immunization programmes mostly depend on the correct maintenance and manipulation of the vaccines to be used, i.e. perfect maintenance of the cold chain. Therefore, we decided to carry out a systematic review of the literature on the cold chain and vaccines, to identify daily practices in vaccine sites.

A literature search was performed in the main medical databases for documents published between 1990 and 2005, including those performed by means of a survey and/or inspection of vaccine sites that provided the following data: a designated health officer, availability of a thermometer with maximums and minimums, refrigerator temperature at the time of the visit, and temperature control and registration. For all the variables, the mean prevalence was calculated with a 95% confidence interval.

Three hundred seventy-seven articles were found; 31 were initially selected and 13 were finally included. In 72.21% of the vaccine points, there was an officer responsible for the vaccines, but only 61.43% knew the optimal temperature range. Fifty-five percent of these points had a thermometer with maximums and minimums and only 26.88% carried out temperature controls and registrations at least once per day.

Important shortfalls were detected in cold chain maintenance in all selected articles, jeopardizing the effectiveness and efficiency of immunization programs.