RESUMEN
Four years after the first visit seventeen public health units were visited again and evaluated as to standards of storage recommended by the Brazilian Immunization Programme. In 100% of the units, refrigerators and proper inside location of vaccines in the refrigerator were adequately or regularly maintained and checked, respectively. However, when control of temperature was checked, only 64.7% presented adequate storage conditions. In 94.1% of the units, health workers complained of lack of immediate technical support in emergency situations. In 55.2% the titers vaccine samples of were under the minimal recommended potency. It is necessary that the factors concerning the cold chain be continually evaluated so that the quality of the vaccines that will be used is not affected.