| live viral vaccine potency: an index for assessing the cold chain system. | this study was carried out in the states of lagos, oyo, osun, nigeria and was designed to assess the efficiency of the cold chain and the potency of the vaccines from the national cold store through to the vaccination centres. storage equipment was inspected and oral polio, measles and yellow fever vaccines were tested for potency. all 27 centres studied had adequately trained staff and storage was shown to be adequate at the national and state cold store level. however, vaccines were adversely ... | 1996 | 8979747 |