POST 00490E : PROTECTION OF MORE COLD-SENSITIVE VACCINES

POST 00490E : PROTECTION OF MORE COLD-SENSITIVE VACCINES Follow-up on Posts 00391E, 00400E, 00412E, 00419E, 00428E, 00475E, 00480E, 00482E and 00484E 21 August 2002 ______________________________________________________________________ John Lloyd (mailto:[log in to unmask]), Carib Nelson (mailto:[log in to unmask]) and Anton Widjaya, from PATH report the salient points that came out of a meeting on prevention of freezing vaccine in the cold chain in Jakarta early August. They also indicate some points that will be researched in Indonesia in the near future. ______________________________________________________________________ At a meeting on prevention of freezing vaccine in the cold chain last week in Jakarta, Indonesia some interesting points came up on this issue: - we do not know the effect of sub-zero temperatures (-1° to -9°C)on the potency of freeze-sensitive vaccines while they are in the liquid 'super-cooled' state, nor how stable is the liquid state. If the potency reduction is insignificant and the 'super-cooled state' stable, then we may not have a problem. Indonesia will test HepB vaccine only. - water-filled icepacks, while avoiding the freezing of vaccine, have to be cooled in refrigerators; capacity may be insufficient, vaccine in the same fridge may be exposed to heat and the fridge may not be powerful enough to cool the water quickly enough. - the "night-before" strategy, in which icepacks are removed from the freezer the night before they are needed and placed in closed cold boxes appears to be a simple, workable policy and is supported by some data. This is being further checked out by December in Indonesia. - taking vaccines out of the cold chain entirely, either in storage or in transport, requires a "two-speed cold chain" which may create confusion and mixed compliance. - Freezewatch is an essential tool for freeze monitoring and the shake-test is an essential tool for confirmatory checks when the shake-test fails. But both these methods need testing urgently to check for consistency, repeatability, sensitivity etc. Indonesia will test the shake test. - computer temperature monitoring and alarm and stock control systems are needed to manage provincial stores and central stores in order to avoid freezing and to track problem history after the event. These systems exist but they need field trials. The full report will be out soon for those who would like to see it. All the best, John Lloyd, Carib Nelson and Anton Widjaya, PATH ----------------------------------------------------------------------------- ---------------- CONTRIBUTIONS: Contributions to: or use your reply button! The TechNet21 e-Forum welcomes new subscribers who are involved in immunization services. SUBCRIBE: To subscribe, send an e-mail to: Leave the SUBJECT area BLANK, do not type anything. In the body text, just write: Subscribe TECHNET21E Surname Name Do not use any accents in your name and surname. UNSUBSCRIBE: To unsubscribe, send an e-mail to: Leave the SUBJECT area BLANK, do not type anything. In the body text, just write: Unsubscribe TECHNET21E ------------------------------------------------------------------------------ ARCHIVES Archives of posted messages classified by month starting with 1 January 2000 are accessible to all TechNet21 subscribers at the following site : http://listes.ulaval.ca/listserv/archives/technet21e.html Archives for postings prior to January 2000 can be found at the following site : http://www.who.int/vaccines-access/Vaccines/Vaccine_Cold_Chain/Technet Or by request to the Moderator at mailto:[log in to unmask] ------------------------------------------------------------------------------ Archives for files (documents) are under revision to clean old documents and drafts that are already replaced with new ones, and will be made available soon at a specific site. ------------------------------------------------------------------------------ The World Health Organization and UNICEF support TechNet21. The TechNet21 e-Forum is a communication/information tool for generation of ideas on how to improve immunization services. It is moderated by Claude Letarte and is hosted in cooperation with the Centre de coopération internationale en santé et développement, Québec, Canada (http://www.ccisd.org) -----------------------------------------------------------------------------