Dimanche 22 Janvier 2012
  3 Replies
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While immunization partners involved in supporting vaccine supply chain (WHO, UNICEF’s CCL and Project Optimize ...) are collaborating and building on each others’ experiences, there are several pertinent questions to the field yet to be addressed: 1. Questions related to standby generators: Although the EVM assessment tool pays lip service to standby generators, it does not go into details and does not examine the size (power generated) and its adequacy. In addition program managers and immunization specialist are completely dependent on electricians to determine the size of the generators in order to replace the old one or to purchase new ones. Simple tools can be developed to enable immunization program managers and vaccine store staff to estimate the electrical load and to determine generator sizes and therefore give them power to negotiate and make informed decisions. 2. Questions related to cold rooms versus refrigerators: Is there any clear line for determining when to opt for a number of refrigerators over one cold room? There must be a relationship between capital and running cost of cold rooms versus refrigerators. This question is particularly relevant during the planning stages of a new store or planning for expansion of the existing stores. At what volume of vaccines is a cold room(s) justified? There are many technical and economic issues involved in this decision and they may change in different situations - What are the pros and cons? It is now time for empowering program managers to make informed decisions and enable them to negotiate with equipment providers. The other question to be addressed is the efficient number of walk-in cold rooms for an estimated volume of vaccines. Do we install one large walk-in cold room or do we go for a certain number of smaller cold rooms to sum-up to the same volume of the large cold room? 3. Questions related to the proportion of cold chain equipment from those tested and standardized and those locally purchased: We know that large countries like China, the Philippines, Egypt, Iran, etc purchase their cold chain equipment from local markets. We also know that cold chain equipment provided by UNICEF, GAVI and WHO are usually from tested and pre-qualified equipment. However, the information unavailable to us is the proportion of locally made and pre-qualified cold chain equipment used for vaccination programs. Even a rough estimate can help developing guidelines for those programs purchasing equipment from local markets to select the best available option. It is quite necessary for the program managers to be informed on how to select the most suitable refrigerators from a variety of available domestic ones? This will apply to all other cold chain equipment. 4. Questions related to number of programs where vaccine storage, distribution and handling are integrated with other pharmaceuticals and medical supplies: Do we know how many countries or programs are storing and particularly distributing vaccines with other medical supplies? Are these programs successful? What are the challenges involved in integrating the vaccine supply chain with other medical supplies? It was important to note that Project Optimize looked at the possibility of involving private sector in vaccine storage and distribution in South Africa and Thailand but did not look at the question of integration of vaccine with other medical supplies in the context of government run supply chain.
12 years ago
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#2383
Thank-you for raising these questions, Mojtaba (And thanks to Gregory Kiluva for his help in answering) 1. Questions related to standby generators: This is a valid point that we agree with. UNICEF is already in the process of developing a simple tool to determine the required generator size/rating for different cold rooms. Please email [email protected] if you would like to add your suggestions for this tool 2. Questions related to cold rooms versus refrigerators: Again, a very good point and we agree that there is a need for some guidance on this, especially with the expanded needs of storage with the addition of new vaccines and other essential health commodities that require refrigeration. PIS 1997 Page 6 provides some information on type of equipment needed by population served, but the information is old ( we have new vaccines) and not exhaustive. The WHO document " Guideline for establishing or improving primary and intermediate vaccine stores" page 28 also touches slightly on that but does not give any detailed information. As Mojtaba points out there are both technical and economic issues, including the impacts and risks of failure of individual items of equipment. 3. Questions related to the proportion of cold chain equipment from those tested and standardized and those locally purchased: The fundamental issue here is whether the equipment used is fit for the purpose of storing vaccine. We recommend using WHO PQS equipment because this testing has already been done. It is possible to also test locally manufactured equipment to see if it meets the WHO standard; as well as ongoing monitoring of its performance in the field. Not clear why the % locally purchased is important; having an up-to-date inventory with functional status isthe more important issue, and form this these date could be derived, as well as the performance of different kinds of equipment over time, 4. Questions related to number of programs where vaccine storage, distribution and handling are integrated with other pharmaceuticals and medical supplies: I will be interested to hear from others, but we are not aware of successful integration of vaccines with supply of other commodities. In theory this is a good idea and should lead to efficiencies. But integration of different supply chains requires (1) high level of technical capacity for planning, foretasting , supply chain alignment, distribution networking , etc; (2) efficient transportation and warehousing systems and (3) functional and up to date information systems. Mojtaba, thanks again for raising these issues, and we look forward to hearing other comments Best Oz Dr Osman David Mansoor [] Public Health Physician Senior Adviser EPI (New Vaccines) []United Nations Children's Fund [] 3 UN Plaza, New York, NY 10017 (room 840) Phone: +1 212 326 7410 (direct) Fax: +1 212 8246460 Email: [email protected]
12 years ago
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#2384
Many thanks to Mogens Munck for his responses 1. Questions related to standby generators: You could very well have included sizing of voltage stabilizers.. Sizing the generator is not too difficult. It was explained in some details in the old “Product Information Sheets”, pages 22-26, but unfortunately UNICEF/WHO do not publish this valuable catalogue any longer. A generator shall have enough power to start up the compressor(s) of the refrigerator unit(s). The power required for starting up a compressor is considerably higher than the power required once the compressor is running. In this respect the P.I.S. says that the start and running currents should be determined by using an ampere meter, but this is somewhat illogical, because if the generator has to be specified for refrigeration units to be purchased, no units are available, we can only rely on the manufacturers´ compressor specifications, which most probably do indicate at least the running current. However, if we do have already the refrigeration units, it is easy to read the running current, but as the start current is only there for a very short moment (probably less than a second) the reading of the start current becomes difficult, if not impossible. However, practice has established a rule of thumb that has proved to be useful, it says: The current required for a very short moment at starting up a compressor is 4-5 times the running current. Example: A refrigerator compressor of nominal 1 kW power requirement will require a voltage stabilizer/generator of 4-5 kW. A compressor for a walk-in cooling room of 3 HP power requirement, will require a standby generator of 10-12 HP. Suggestion: Develop step-by-step procedures for sizing generators and stabilizers taking as examples the step-by-step procedures for sizing a cold room that can be found in the WHO publication: “Guidelines for improving and establishing vaccine stores”. 2. Questions related to cold rooms versus refrigerators: I suggest that you do not make this too theoretical and complicated, because: running cost has never been established for cold chain equipment. You ask: “At what volume of vaccines is a cold room(s) justified”? Simply when the cost of a high number of refrigerators/freezers is higher than the cost of procuring a cold/freezer room. Again the WHO publication: “Guidelines for improving and establishing vaccine stores” is excellent for sizing the storage requirements and it specifies that WIC/WIF is justified once the number of fridges/freezers is higher that 5-6. I suggest using the procurement cost. You ask: ” Do we install one large walk-in cold room or do we go for a certain number of smaller cold rooms to sum-up to the same volume of the large cold room”? Again I suggest that you do not turn theoretical. Is it not better to have available middle size WIC/WIFs of a size that is suitable for storing one antigen? As far as possible a room for each antigen instead of a huge room that can store several antigens. Also for security reasons it would be better not to have too huge rooms, as an equipment break down then becomes much more problematic. 3. Questions related to the proportion of cold chain equipment from those tested and standardized and those locally purchased: I do not agree at all with you! First, you do not need to advise programme managers who are smart enough to procure locally made equipment, now that we sooner or later are converting to “Cool Chain” instead of cold chain. Second, our colleague Soeren Spanner has already explained what is required of locally made equipment. What does it help you to know who buys and how much? 4. Questions related to number of programmes where vaccine storage, distribution and handling are integrated with other pharmaceuticals and medical supplies: Yes, not very well executed by Project Optimize. They could have done better!!! Since I started working in Essential Drugs Programmes (1993) I have advocated integration of drugs and vaccine logistics, but immunization programmes are vertical programmes and WHO has done very little in order to change this verticality concept. The Essential Drugs Programmes have, in general, far more qualified staff available for logistics work than the EPI programmes. Example: African countries use pharmacy technicians for drug logistics, and these technicians have 3-4 years technical education, very much required for handling drug programs that have up to 500 items to be delivered to up to 2000 users every month on a (the ZEDAP program in Zimbabwe in the 1980s and 1990s). THESE PROGRAMMES HAVE STAFF, STORAGE AND TRANSPORT EQUIPMENT AVAILABLE FOR STORING ALSO VACCINES.
12 years ago
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#2385
Dear Technet Moderator, Last week Mojtaba brought to our attention some issues that are still pending a resolution. I would like to add to the list two other issues that to me are extremely important: Revision of the Controlled Temperature Chain (CTC)..... The CTC concept was first dealt with in the TLAC committee and then in the committee that succeeded TLAC, i.e. IPAC. The official meeting reports of TLAC and IPAC can be obtained from the WHO web page, and I will be referring to these reports, particularly the report on the last TLAC meeting held in September 2009, in which my colleague Soren Spanner and I proposed: 1.1 Moving to a "cool chain" 1.1.1 Use of domestic refrigerators at the Healthcare Centre Level 1.1.2 Use of cool rooms at healthcare facility level 1.1.3 Use of eutectic packs to avoid freezing 1.1.4 TLAC Findings, Conclusions, and Recommendations on the "Cool Chain" Soren and I used the term "Cool Chain", but in the same meeting the term "Controlled Temperature Chain" (CTC) was coined. The key rationale was that the stability of most vaccines is such that they may safely be kept at +20°C to +25°C for up to one month without significant loss of potency. Please see Tables 9 and 10 in the WHO publication: "Temperature Sensitive Vaccines", published in 1996. However, also the fact that the new vaccines already introduced into EPI and those to come, will take up immensely more space than the traditional 6 antigens, was important to us. For my own part I believed that the VVM would facilitate the implementation of our proposals, but it turned out that the VVMs are only used on 30% of the vaccines used in immunization programs, and that VVMs are not being used by PAHO. Please see relevant TLAC and IPAC reports. Soren on his part proposed the use of domestic refrigerators at the Healthcare Centre level, and I proposed the use of cool rooms (walk-in units without refrigeration equipment, but with a simple air condition unit, bringing the cost of a WIC down to one third), at the same level. Anyone interested in our proposals can read the TLAC report of the September 2009 meeting, or even better our very detailed proposal, presented in our own writing, which is attached. Implementation of our proposals would imply changing the temperature range at which our vaccines are presently to be kept: 2-8 degrees Celsius. WHO is therefore set to move cautiously with the implementation of CTC, and in this respect I propose that interested readers read the meeting report of the IPAC meeting held in November 2010. However, since November 2010, WHO/IPAC has not published anything regarding CTC, i.e., in 2011, nothing at all is reported regarding CTC. Would it be too much to request information from WHO on progress in implementation of CTC as CTC will have far reaching consequences for the cold chain? Revision of the multi-dose vial policy (MDVP) and related topics .. This topic has been pending for the last many years according to relevant TLAC and IPAC reports. It has been on the agenda of all TLAC and IPAC meetings, particularly the first IPAC meeting in June 2010, from which I copy: [/b] 3.1 Background [b] The 2002 "Multi-Dose Vial Policy" (MDVP) was created to allow health workers to keep opened vials of indicated vaccines - where it was safe to do so - for subsequent immunization sessions, provided that certain cold chain and handling requirements were met. Dr Eggers listed new challenges faced with use of MDVP. New, multi-dose, liquid vaccines containing varying amounts of new preservative may be mistakenly kept for longer time periods than optimal, as health workers generally associated liquid vaccines with those that could be kept. Also, fractional doses may be used from a single-dose unpreserved vial, thus rendering vaccine unsafe, if kept. In other cases, adequately preserved new combination vaccines may be mistakenly discarded, thus rendering MDVP too wasteful. These challenges mandated a need for MDVP revision, including development of a new visual cue that should enable a vaccinator, just by looking at the vial, to clearly distinguish between a vial that can be kept and one that has to be discarded regardless of formulation. Full reading of the relevant IPAC reports will impress on the reader, how complicated EPI work has become. WHO/IPAC has reported very well on the progress of work regarding revision of MDVP, but one also gets the impression that there is a long way to go still. Implementation of CTC and revision of MDVP are to me two very important pending issues, and I recommend anyone interested in EPI work to read the publicly available TLAC and IPAC reports. Regards, Mogens Munck The cool chain concept
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