Tuesday, 18 April 2000
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Post00243 VACCINE FREEZING 18 April 2000 CONTENTS 1. CHANGING VACCINE STORAGE LOWER TEMPERATURE LIMIT FROM 0 TO 2 DEGREES? 2. MEDECINS SANS FRONTIERES & VACCINE STORAGE TEMPERATURES 3. COOL FACTS: FREEZING IN ICE LINED REFRIGERATORS 1. CHANGING VACCINE STORAGE LOWER TEMPERATURE LIMIT FROM 0 TO 2 DEGREES? This discussion continues from Post00239 VACCINE FREEZING on 06 April 2000 and Post00231,14-15 March 2000, and Post0218 on 18 January 2000. Technet discussions have agreed on the need to prevent the freezing of vaccines in refrigerator storage. Some engineering, user, and cost constraints were identified as barriers to setting new temperature range specifications. Mary Catlin, PATH, proposed in Post0218 that, considering zero vaccine degree storage and the risk of freezing HepB - a vaccine coming into wide routine use, that we modify the current recommendation to +2'C to +8'C on the TECHNET Forum. The current EPI vaccine storage recommendation for refrigerator storage is for one month at 0 'C to +8'C. Other regions of the world and other countries recommend +2'C, or even +4'C to 8'C. Many manufacturers label their vaccine vial for storage between 0'C and 10'C. * In today's post, Hans Everts, WHO/V&B/EPI, argues against changing the storage temperature recommendations and discusses other approaches to the problem. Action, comments and additions please: [[email protected]][email protected][/email] or use your reply button ___________________________________________________________________________ From: [[email protected]][email protected][/email] Date: Mon, 10 Apr 2000 10:36:45 +0200 To: Technet Moderator Subject: Vaccine Freezing Dear Allan, I do not think a change in the minimum temperature from 0?C to 2?C is the best way to prevent freezing of vaccine. There are a number of reasons and other options: 1) With the current test procedures an appliance is tested with optimal thermostat setting. Once in the field the ambient conditions are different and the thermostat setting is changed, often leading to freezing. When we can, with the current procedures, prevent freezing in the laboratory, we do not really know what can happen afterwards. Therefore, we are working on changing the specifications and test procedures to make sure freezing is impossible under any condition.Soren Spanner is figuring out if we can define a truly worst case test scenario under which appliances should be tested. The result should be that we get appliances properly protected against freezing. 2) At present we accept minimum temperatures that go slightly below zero as marginal failures. Such appliances got a warning in the comment box in the PIS. This is very unsatisfactory. From of now, we will no longer accept these marginal failures and request manufacturers to either prevent freezing occurring, or ensure proper protection of vaccines by other means. This was already one of the decisions taken in the context of the temperature zones. 3) The specifications for cold boxes and vaccine carriers are between 0-8?C and there is a good reason for that: the ice packs are 0?C as long as they are frozen. I do not think different temperatures for different types of equipment will contribute to clarity. 4) A major problem with increasing the minimum temperature occurs for ice-lined appliances. The ice-lining is only useful when the tubes/ice packs can be frozen during the period when electricity is available. This inevitably means that the temperature is close to 0?C in the vicinity of the ice-lining. A requirement of a minimum temperature of 2?C would imply either that the ice-lining should not freeze, which means it looses its function all together, or that additional insulation should be installed between the icelining and the vaccines. The second option would make it very expensive and/or would considerably reduce vaccine storage capacity. 5) Limiting the temperature range from 2-8?C is asking for price increases, which in its turn will lead to the purchase of cheaper and not-tested appliances, that are usually much less protected against freezing. * In order to achieve better protection against freezing, I therefore suggest maintaining the range from 0-8?C, or even 0-10?C, but to focus on the specifications, test procedures and technical changes (electronic or no thermostat, physical isolation of areas with negative temperatures, etc.) making he occurrence of negative temperatures impossible. Some of these solutions may take some time, but some can be implemented immediately. In the coming edition of the PIS we should try to get rid of several warnings regarding freezing. Regards Hans Everts EPI Technical Officer WHO Geneva Tel: 00 41 33 791 3863 ____________________________________*______________________________________ 2. MEDECINS SANS FRONTIERES & VACCINE STORAGE TEMPERATURES Field action by MSF is kindly described in this message from by Menno Goedhart, MSF/A. Menno's comments on the use of refrigerator modifications kits in Albania is an instructive reminder of field realities. MSF uses a vaccine storage temperature range of +2'C to +8'C. Menno adds to the clarifications on vaccine label color codes - discussed in Post00231, and suggests adding the new vaccines to the list. Action, comments and additions please: [[email protected]][email protected][/email] or use your reply button ___________________________________________________________________________ Refrigerator modifications were discussed in previous postings. See TECHNET Forum posts 00214, 17 January 2000, and Post0226 on 8 February 2000. Guidelines and plans for refrigerator modifications were posted in Post00231 on 15 March 2000. ___________________________________________________________________________ Date: Mon, 10 Apr 2000 11:32:24 +0100 From: [[email protected]][email protected][/email] (Menno GOEDHART) Subject: Re: Post00239 VACCINE FREEZING To: [[email protected]][email protected][/email] Dear Allan, Here is a bit about how MSF (Medecins sans Frontieres) is dealing with vaccine storage temperatures. In our field guideline we stress the point of storing vaccines between 2 and 8 degrees C. Starting 1993, when it was apparent that Hep B was becoming part of the EPI in some countries. A special chapter deals with vaccine (and ergometrine, insulin, test kits etc) storage in cold countries. We were working in Albania and Georgia until 1995, doing a cold chain project for almost the whole country and the province of Adjaria respectively, distributing cold chain material, fridges and freezers with all paraphernalia and giving training on it's use and maintenance. In Albania we distributed small upright household fridges, with a (Dutch custom made) insert of an aluminum vaccine storage cabinet with door, surrounded with ice packs filled with water to increase cold mass. When we later when came back to Albania for the polio vaccination campaigns: (anecdotally) the aluminum inserts were not used in most clinics, or at least not inside the fridge. And often vaccines were kept in them outside the refrigerator during vaccination sessions. In our projects in the FSU [Former Soviet Union] we had translations made into Russian of the do's and don'ts on the vestfrost fridges, and we translated the 0 degree English into 2 degree C Russian. I am interested in the color coding of vaccine vials; as far as I know: DTP yellow, TT: Green, DT: Lime, Measles: orange/red, BCG: blue. official color coding for other vaccines? We make mistakes, and color coding might help. All the best, Menno Goedhart Technical advisor MSF Amsterdam _________________________________*_________________________________________ 3. COOL FACTS: FREEZING IN ICE LINED REFRIGERATORS Soren Spanner, WHO/SEARO, posts the logs of 2 years of temperature and voltage data on freezing temperatures at the top basket in ice lined refrigerators in India. Soren suggests that under the field conditions user adjustment of the thermostat is problematical, and promises a Technet proposal. * Fixed, accurate refrigerator thermostats are under discussion. Action, comments and additions please: [[email protected]][email protected][/email] or use your reply button __________________________________________________________________________ The files are available for download in Adobe? Actrobat format The file "ILR-Temperature-annex1.pdf" is a quick download. * The file "ILR-Temperature-annex2.pdf" is a long download for anyone using a dial-in Internet connection, or whose mailbox has a file size limitbelow 3.5 Mb.. Go to the website ftp://ftp.acithn.uq.edu.au/Technet/1-ClickHereForTECHNETfiles/VAX-Freeze/ and click on the files: ILR-Temperature-annex1.pdf 29.8 kb ILR-Temperature-annex2.pdf 3.1 mb or Send an email to: [[email protected]][email protected][/email] and send the message: get technet ILR-Temperature-annex1.pdf get technet ILR-Temperature-annex2.pdf ___________________________________________________________________________ From: "Spanner, Mr. Soren" To: "'Technet Moderator'" Subject: RE: Post00239 VACCINE FREEZING Date: Thu, 6 Apr 2000 11:45:38 +0530 Dear Allan, Talking about freezing of vaccines. I attach for information some "cool facts" The temperatures shown in the graphs are all measured in the centre of the bottom of the upper basket [of ILRs]. The study was done in Madhya Pradesh, India over a period of approximately 2 years. The low temperatures are due to wrong user adjustment of the thermostat, but reflects a "real life situation", at times the thermostat is set correctly and at times it is not. The gaps in the voltage graphs are due to logger battery failure. The only way, I believe, we can avoid the low temperatures in ILRs is by changing the test specifications for ILRs, maybe eliminate the thermostat and have a fixed setting by an electronic thermostat. The specs currently are made for optimal thermostat setting and I think that is asking too much of the users. I believe that we should leave the vaccine storage range between 0 and 8'C, so as not to confuse users and to allow the freezing of the ice-lining. I will draft a proposal. best regards soren Soren Spanner Technical Officer Cold Chain & Logistics Tel.: +91 11 331 7804 Fax.:+91 11 335 2106 ____________________________________*________________________
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