Jeudi 6 Avril 2000
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Post00239 VACCINE FREEING 06 April 2000 CONTENTS 1. CHANGING VACCINE STORAGE LOWER TEMPERATURE LIMIT FROM 0 TO 2 DEGREES? 2. FREEZE VVMS? Moderator's note: Corrections: 1. The previous TECHNET Forum post on Tuesday 4 April was Post00238 not 0338 as indicated in the post.Post00237 was incorrectly identified as Post00337. 2. If you had difficulties downloading the file AideMemoire- HealthCWaste-3.PDF as referenced in Post00237, WASTE MANAGEMENT + INJECTION SAFETY, on 30 March 2000, please note that this file is now available for download. Go to the website ftp://ftp.acithn.uq.edu.au/Technet/1-ClickHereForTECHNETfiles/ go to the folder "Waste" and click on the file: AideMemoire-HealthCWaste-3.PDF or Send an email to: [[email protected]][email protected][/email] To get the file - send the message: get technet AideMemoire-HealthCWaste-3.PDF ____________________________________*______________________________________ 1. CHANGING VACCINE STORAGE LOWER TEMPERATURE LIMIT FROM 0 TO 2 DEGREES? Continued from Post00231, VACCINE FREEZING, 14-15 March 2000. The current EPI vaccine storage recommendation for refrigerator storage is 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. Mary Catlin, PATH, proposed in Post0218 that, considering the risk of zero degree storage on HepB - a vaccine coming into wide routine use, that we try to modify the current recommendation to +2'C to +8'C on the TECHNET Forum. The discussions so far have see to the need to raise the lower vaccine storage temperature limit for vaccines stored in refrigerators, but have identified some engineering and cost constraints. Extending the proposed change beyond electric refrigerators appears to be problematical. Other technology based solutions are not in advanced states of development. Terry Hart, IT Power India, in Post0226, pointed our that the accuracy of built in refrigerator thermometers can be in error by as much as 4 degrees, using existing technologies and called for a new specification for refrigerator thermometers. In Post0226, Michel Zaffran, WHO/V&B, raised 3 constraints that need to be evaluated if we are, in fact, going to change a vaccine storage equipment specification. * Anthony Battersby, FBA, discusses this further and concludes that we need the freeze sensitive VVM. * See item 2 of this post for discussion of the requirements for a Freeze Vaccine Vial Monitor. Contributions, comments and additions please: [[email protected]][email protected][/email] or use your reply button ___________________________________________________________________________ Date: Wed, 15 Mar 2000 05:49:53 -0500 From: Anthony Battersby To: Technet Moderator Subject: Post00231 VACCINE FREEZING Dear Allan, Much of the equipment now in use (eg ILRs and RCW42) for storing vaccines was designed when the specification was +4/+8degC. In addition I have the impression that most manufacturers specify +2/+8degC on their package inserts. The problem with supercooling is that when a supercooled vial is shaken it immediately changes state and freezes, I have witnessed this phenomenon on a number of occasions. So it may be OK in the refrigerator but is damaged as soon as it is taken out to administer. Paradoxically the countries that use domestic equipment are often those that are not the poorest. They may have national regulations that require that the directions on package inserts take precidence over any other guidance. In my experience in such countries it is difficult to convince a nurse that she should ignore the package insert. Should the matter ever be tested in court, for example because a child contracted Hep B after being immunised with a vaccine damaged by freezing, if storage conditions did not comply with manufacturers advice, where would liability lie? At the Washington Technet we were shown a cabinet that could be inserted into a domestic refrigerator to improve its performance, I think it came from the Philippines, what happened to it? Eric et al's manual looks excellent. Are there any data to show by how much these modifications will improve performance and by how much they reduce storage capacity? It would be useful to have an example for say an 80L and 200L refrigerator. Michel is correct, what matters is the temperature of the vaccine and to be assured of this we need the freeze sensitive VVM. What is the time frame for this device being available and how high a priority is it being given? Anthony ____________________________________*______________________________________ 2. FREEZE VVMS? Following the discussions in TECHNET Forum Post00231 VACCINE FREEZING, 14-15 March 2000, the forum received an interesting enquiry from Richard Hounslea, Loughborough University, UK. Richard is "working for a company which specializes in time/temperature indicator technology and is anxious to develop a freeze indicator which would satisfy the demand highlighted in the forum." Debra Kristensen, PATH, replies and makes available an old feasibility analysis on freeze prevention that includes a preliminary product specification for freeze indicators. Debbie kindly adds her list of references about freezing in the cold chain, and has indicated that it needs to be updated. Thanks are due to Richard and to Debbie for sharing this discussion. * Technet members should review the old draft specifications with the aim of getting the indicator that we think will improve vaccine and cold chain management. Our recent experience with heat sensitive VVMs on oral polio vaccines should be helpful in specifying a freeze indicator and bringing it into use. Contributions, comments and additions please: [[email protected]][email protected][/email] or use your reply button ___________________________________________________________________________ These files are available for download: FreezePrevention-References-1.PDF FreezePreventionFeasibility-4-1996.PDF Go to the website ftp://ftp.acithn.uq.edu.au/Technet/1-ClickHereForTECHNETfiles/VAX-Freeze or Send an email to: [[email protected]][email protected][/email] To get the file - send the message: get technet FreezePrevention-References-1.PDF get technet FreezePreventionFeasibility-4-1996.PDF ___________________________________________________________________________ From: Richard Hounslea To: "'Technet Moderator'" Subject: RE: Post00231 VACCINE FREEZING Date: Fri, 24 Mar 2000 10:52:49 -0000 Dear Allan, I write to you in reference to the growing need for a Vaccine Vial Freeze Indicator. I am working for a company which specialises in time/temperature indicator technology and is anxious to develop a freeze indicator which would satisfy the demand highlighted in the forum. I would be most grateful if you could clarify any of the following; 1. The different types of vaccine, both current and predicted, that the indicator would be required to monitor. As far as I can ascertain DPT, HepB, TT and DT are of most concern. Are there any others? 2. An estimate of the volume of indicators required. 3. Whether different vaccines will require different performance characteristics from the indicator (time/temp, threshold etc.) 4. Requirements for the indicator, for example, interpretation considerations (I am assuming that because the indicator will be 'dual threshold' it will need to combine two different indicators, perhaps even requiring different technologies). 5. Requirements for the indicator in terms of size, attachment to the vial, cost etc. 6. The integration of the monitor with other forms of indicator which may be used inside a refrigerator. Any information that you could provide which will enable us to develop a completely satisfactory indicator would be gratefully received. I look forward to your reply and the opportunity to discuss this with you further. Richard Hounslea Loughborough University United Kingdom ---- From: Allan Bass [mailto:[email protected]] Sent: Sunday, March 26, 2000 3:23 PM To: [[email protected]][email protected][/email]; Kristensen, Debra Cc: Technet Moderator Subject: Freeze VVMs : Fwd: RE: Post00231 VACCINE FREEZING Dear Hans and Debbie, This came in on the weekend. A time - temperature indicators technology company expressed an interest in Freeze VVMs following Technet Post00231 on 14-15 March 2000. I have sent Richard the E6/IN.3 spec appended to the end of this email and referred him to the VVM material in the WHO V&B Document Centre. * We need - (or do we have some unpublished spec?) a Freeze VVM spec - including label placement & max dimensions and possibly overlay/compatibility with the existing heat VVM. What Action next? regards, allan ---- E6: Temperature monitoring devices 12 Equipment performance specifications and test procedures FREEZEWATCH INDICATOR, IRREVERSIBLE Specification reference: E6/IN.3 Applies to procedures: E6/PROC/3 Date of last revision: 1 January 1998 Temperature threshold: -5?C, irreversible colour change or 0?C, irreversible colour change Time/temperature function: None Features: Colour spot change at threshold temperature Application: Packed with adsorbed vaccines (DT, DTP, TT and Hepatitis) to warn of exposure to temperatures below -6.5?C for the -5?C model and -1?C for the 0?C model. ---- From: "Kristensen, Debra" To: Technet Moderator Subject: RE: Freeze VVMs : Fwd: RE: Post00231 VACCINE FREEZING Date: Mon, 27 Mar 2000 11:57:57 -0800 Allan: Thanks for the information. I am enclosing 2 documents that might be useful to share with Richard: 1) An old feasibility analysis on freeze prevention that includes a preliminary product specification for freeze indicators. 2) My list of references about freezing in the cold chain. Regarding market size, the following information may help. For the year 2000, UNICEF will procure the following quantities of freeze-sensitive vaccines: DT = 115,000 vials DTP = 9 million vials Td = 110,000 vials TT = 10 million vials Soon we will also know about the quantities of hepatitis B vaccine that the Global Fund intends to purchase in late 2000/early 2001. Does someone have information on the quantity of hepatitis B vaccine that PAHO is purchasing in 2000? Finally, I would be willing to have a discussion with Richard about the potential for product development collaboration between PATH and the university. All the best, Debbie --- From: Richard Hounslea To: "Allan Bass (E-mail)" Subject: Post 00231 VACCINE FREEZING Date: Wed, 29 Mar 2000 10:50:39 +0100 Dear Allan, Thank-you for you reply to my e-mail concerning specifications and requirements for the Freeze VVM. The information I received from Debra Kristensen was most useful. There are however a couple of points which I would be most grateful if you could clarify. In the feasibility analysis which Debra e-mailed to you, point '3' of the section 'Proposed Technology' states, "The indicator colour must not cause confusion with EPI colour codes or VVMs on vaccine vials". I have searched through the Equipment Performance Specifications and Test Procedures document and have found no reference to 'colour codes' as such, only the specifications concerning the rate at which the heat VVMs change colour (start-points, end-points etc). Perhaps they are the same thing? Obviously if would be of no use to you if we manufactured a Freeze VVM which used the wrong colours! I would also welcome your thoughts on the time lag required for the indicator to activate and the rate at which the "conversion" should occur". This was highlighted in point '1' of the same section of the feasibility study. I realise that it may be a little too early to clarify all of the specs and requirements, but any further information would be most appreciated. I look forward to hearing from you in due course. Richard Hounslea Loughborough University UK ---- From: Allan Bass [mailto:[email protected]] Sent: Sunday, April 02, 2000 10:14 PM To: Richard Hounslea Cc: Kristensen, Debra; [[email protected]][email protected][/email] Subject: Re: Post 00231 VACCINE FREEZING Dear Richard, The EPI vaccine colour codes refer to plastic caps, Au bands, and labels on multidose vials - i.e. "Orange" for Measles vaccine, and so on. I cannot put my hands on the colour code details at the moment - but will them locate soon [As a quick check - I note that they do not appear in the WHO model procurement specifications for vaccines. The VVM colors that I'm aware of are white and shades of blue and purple. Your second question on time lag is a good one. You might check with Debbie Kristensen at PATH. Path worked for more than 15 years on the development of the heat/time VVMs and will have a lot of usability data from the many field trials. Personally - I would think something that tracked the phase change in the vaccine in the vial would be appropriate. I hope that this helps. Debbie is the best person to discuss these issues with. Please keep me informed. regards, allan ---- From: "Kristensen, Debra" To: Richard Hounslea Cc: [[email protected]][email protected][/email] Subject: RE: Post 00231 VACCINE FREEZING Date: Wed, 5 Apr 2000 13:54:52 -0700 Dear Richard: The draft specifications I sent were a few years old. I believe that WHO has since dropped the EPI colour codes. It was my understanding that the colours (e.g., PMS 327 Green for TT, PMS 287 Blue for hepatitis B vaccine...) were incorporated onto the paper label on the vial. But this is likely to be a non-issue now. Perhaps Allan will locate the definitive answer on this. The only VVMs currently available are from LifeLines and they change from light purple (nearly white) to dark purple. However, WHO does not specify a color for VVMs. They only specify that there must be a shade change from light to dark with heat exposure, but no change in hue. I enclose a copy of WHO's VVM specifications. The time lag is tricky because current recommended storage temperatures for vaccine are 0-8 degrees C and hepatitis B vaccine freezes at approximately -0.5 degrees C. Also, we must take into account the facts that the temperature outside of a glass vial differs from that inside and that smaller quantities of vaccine (i.e., single dose vials) will freeze faster. We could conduct studies on the time taken for a specific quantity of a specific brand of vaccine to freeze and/or to lose potency, but this may not be necessary. We want the indicator to be conservative so that it errs on the safe side, but not so conservative so that vaccine is wasted unnecessarily. It would be ideal if the indicator could be customized to the freezing point of the vaccine, but this might increase the cost. The accuracy of the indicator becomes very important in setting the conversion point. For example, If the accuracy is +/- 1 degree C we may need to set the conversion point at 0.5 degrees C for hepatitis B vaccine to be safe and this is within normal storage temperatures. At this point, it might be best to begin a dialogue about the capabilities of your technology and how it might meet the needs as currently defined. Please let me know if a meeting would be useful. I may be in Europe later this month and we always welcome visitors to Seattle. We could also sign a confidentiality agreement, if necessary. All the best, Debbie Kristensen Technical Officer Program for Appropriate Technology in Health (PATH) 4 Nickerson Street, Seattle, WA 98109-1699 USA Telephone: (206) 285-3500; Fax (206) 285-6619 E-Mail: [[email protected]][email protected][/email]; PATH Web Site: http://www.path.org ___________________________________________________________________________ Feasibility Analysis: Preventing Delivery of Vaccine Damaged by Freezing April 1996 Extracts ___________________________________________________________________________ STATEMENT OF PROBLEM TO BE ADDRESSED Certain vaccines are more at risk from loss of potency due to freezing than to heat exposure. These vaccines include diphtheria, pertussis, and tetanus (DPT), diphtheria toxoid (Dt), tetanus and diphtheria toxoid (Td), tetanus toxoid (TT), and hepatitis B vaccine. In addition, most or all of the vaccines which may come into the EPI in the future, e.g., pneumococcal and hemophilus influenza vaccines are expected to be freeze-sensitive. Freezing can totally and irreversibly damage the efficacy of these vaccines and increase the risk of side effects. Freezing of vaccines can occur when vials are exposed to cold during: * transport in cold boxes with ice or ice packs; * transport as air cargo; * storage or transport in areas with low ambient temperatures; or * storage in cold rooms or refrigerators (especially ice-lined and domestic refrigerators) that are set at inappropriately low temperatures or have nonuniform temperatures within, e.g., cold spots near the freezer compartment. SITUATION ANALYSIS Low vaccine efficacy rates are often attributed to vaccine damage due to freezing. For example, a recent check on the efficacy of TT supplied by UNICEF and transported through the cold chain to Punjab, Pakistan, showed vaccine efficacy rates as low as 24 percent in one district. Studies of the cold chain, i.e., the systems for transporting and storing vaccines from the place of manufacture to the place of administration, have revealed "breaks" in the cold chain during which vaccines were inadvertently frozen. A 1987-88 study published in the Bulletin of the World Health Organization revealed that in Hungary up to 38 percent of DPT was exposed to below-freezing temperatures in the winter. A 1990 study in Australia found that 47.5 percent of tagged hepatitis B vaccine vials were exposed to -3?C or less the majority of them during storage in health facilities. ---- PROPOSED TECHNOLOGY Preliminary freeze indicator specifications: 1. The indicator should exhibit an irreversible, easy-to-interpret, visual response after exposure to the freezing temperature (or a slightly higher temperature) of the vaccine for which it is being used, e.g., -5?C for DPT, DT, and TT and -0.5?C for hepatitis B vaccine. The length of time of exposure at the freezing temperature prior to indicator "conversion" needs to be established with assistance from WHO. 2. The indicator should be small so that it can be used on individual vaccine vials. Ideally, it should be a flat device with a maximum size of one square centimeter to avoid obscuring existing labeling information. The indicator could potentially be detachable and reusable since its useful life spans from point of manufacture until frozen. However, the indicators would need to be collected from end-users and returned to vaccine manufacturers - a task that may be feasible in situations of national vaccine distribution. 3. The indicator color must not cause confusion with EPI color codes or VVMs on vaccine vials. 4. The indicator must be low cost. As with VVMs, the additional cost of a vaccine vial due to the indicator must not exceed the cost of a single dose of vaccine in a 10-dose vial. 5. The indicator must be of a configuration that permits labeling onto vaccine containers at the vaccine production sites without adversely affecting production line speeds.
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