POST00428E : PROTECTION OF MORE COLD-SENSITIVE VACCINES

POST 00428E : PROTECTION OF MORE COLD-SENSITIVE VACCINES Follow-up on Posts 00391E, 00400E, 00412E and 00419E 19 February 2002 _________________________________________________________________________ Carib Nelson from PATH is sharing with us quite an interesting idea about the cold chain. Here is his integral contribution. _________________________________________________________________________ Given the increasing awareness of the possible vaccine damage due to freezing and the fact that some vaccines are freeze tolerant while others are fairly heat tolerant, why don't we consider a 2-track cold chain? One track, the existing cold chain, could handle the freeze-tolerant vaccines OPV, measles, and BCG). The other track, a cool chain, could handle the heat-tolerant, but freeze-sensitive vaccines (HepB, TT, DTP). The cool chain could use a variety of non-freezing options to get the vaccine from the central stores to the child. These cool chain options could include transport at ambient temperature; air-conditioned room storage, cool refrigerators (domestic refrigerators set at 15C), ambient temperature outreach, evaporative coolers, or other cooling approaches. What makes this possible are VVMs on these heat tolerant vaccines. They provide instant feedback about whether vaccines have been exposed to too much heat . We no longer need to be so conservative about he 2-8C cold chain for vaccines that don't require 2-8C environments (and that are harmed by the sub-zero environments that frequently accompany a 2-8C edict). Different countries and regions could easily experiment with some of these different options by running VVM-labeled vaccines through some different scenarios. This is what PATH and the Indonesian MOH are doing in Indonesia where hepatitis B vaccines are being transported from the national to province level at ambient temperatures, stored at district level in air conditioned offices, transported to health centers in cold boxes without ice, stored out of the cold chain at the health center, and then stored at midwives homes and taken for birth-dose outreach at ambient temperatures. So far this experiment is working well without any vaccine spoilage due to heat exposure AND reduced costs for vaccine transport and storage. Again, VVMs provide the ultimate in easy-to-access information about the vaccines' heat exposure at any point in this cool chain. Taking these heat-tolerant vaccines partially or completely out of the current cold chain would increase cold chain capacity, reduce distribution costs, and reduce freeze damage. Significant potential advantages! Carib Nelson Technical Officer ----------------------------------------------------------------------------- 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 New archives of posted messages starting with 1 November 2001 is accessible to all TechNet21 subscribers. To view the archives: http://listes.ulaval.ca/listserv/archives/technet21e.html Archives for postings between 17 August 1998 and 31 October 2001 can be found at the following web site for download starting 1 December 2001. http://www.who.int/vaccines-access/Vaccines/Vaccine_Cold_Chain/Technet 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 the same site. http://www.who.int/vaccines-access/Vaccines/Vaccine_Cold_Chain/Technet ----------------------------------------------------------------------------- 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) -----------------------------------------------------------------------------