TechNet-21 - Forum

This forum provides a place for members to ask questions, share experiences, coordinate activities, and discuss recent developments in immunization.
  1. prabirkc
  2. Supply chain and logistics
  3. Monday, 18 October 2010
In my humble opinion Michel and Robert have asked a useful question. Very often polio or other campaigns displace Measles and Bcg in subdistrict stores. The unwritten convention is to move them to the freezer. Especially since the vials are not as breakable as the old ampoules used earlier Usually field workers keep the diluents outside till they pack the carrier. The overnight in the ILR habit has not caught on yet. Prabir
Robert Steinglass Accepted Answer
We have an observation and a few related questions for WHO and field staff: With the arrival of newer vaccines that must be refrigerated at positive temperatures, many countries will be struggling to adjust their usual practices to accommodate the bulkier vaccines. If there is insufficient space in the positive temperature cold room(s) at national or regional level, staff will be tempted to shift the unreconstituted BCG or measles vaccine to the freezer to make room in the refrigerated cold room for vaccines bulkier such as penta and pneumo, which truly must not be frozen. I realize that WHO no longer recommends that freeze-dried vaccines be stored at -20C degrees. While storing them at minus 20C degrees is not harmful, it is considered *unnecessary*. Instead, these vaccines are recommended for positive-temperature refrigerated storage at all le! vels. Yet, I know that unreconstituted BCG and measles vaccines can be stored at freezing temperatures without damage to the vaccine. Until additional refrigerated space can be located for safe storage at positive temperatures, does WHO consider it reasonable to store unreconstituted BCG and measles at freezing temperatures? If so, at which levels of the cold chain? What about the diluents for these vaccines? Is there any risk, when diluent is packaged in the same primary container as the vaccine, that freezing would break the glass amp or vial in which the diluent is packaged? Would the risk depend on the manufacturer's specific product?" Robert Steinglass and Michel Othepa 
  1. more than a month ago
  2. Supply chain and logistics
  3. # 1
James Cheyne Accepted Answer
You are correct that there is no restriction on storing freeze-dried vaccine at freezing temperatures - it is simply unnecessary. In case of necessity however, for example when there is no refrigerated space available, freeze dried vaccine CAN be kept at temperatures below freezing. The diluents however should NOT be frozen. If the diluents are frozen there is a strong possibility that the vials containing the diluents will fracture. Diluent may be kept at ambient temperatures at all levels of the supply chain except at the immunization site where they need to be cool before being mixed with the vaccine. If the diluents are stored separately from the vaccines special procedures will be needed to guarantee that the correct diluent is shipped with the correct vaccine. For example, diluents for measles vaccine should NOT be used with BCG vaccine or Japanese encephalitis vaccine. The storage measures a! bove should only be used under emergency conditions and until enough refrigerated space can be found. Apart from the additional cost of keeping vaccine frozen instead of simply cold, using up freezing storage space unnecessarily will one day create a shortage of space for vaccines that need to be kept frozen.  This brings up a second issue: if there is inadequate space for a new vaccine currently being added to the EPI and an estimate needs to be made to enlarge the stores, you may wish to consider also looking at the storage needs for the NEXT new vaccine and upgrade the supply chain for the future at the same time. You don't tell us which country you are referring to but many countries are planning to introduce new vaccines at two, three or four year intervals and since changes to the supply chain take time you will not only solve your storage problems for today but also solve your storage problems for the future.  James Cheyne and John Lloyd (PATH) and Kone Soulemane (WHO)
  1. more than a month ago
  2. Supply chain and logistics
  3. # 2


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