Post 00412e : Protection Of More Cold-sensitive Vaccines

POST 00412E : PROTECTION OF MORE COLD-SENSITIVE VACCINES Follow-up on Posts 00391E (26 November 2001), 00400E (19 December 2001), 00404E (4 January 2002) and 00406E (Freezing and vaccine efficacy, 5 January 2002) January 2002 __________________________________________________________________________ In Post 00400E, Umit Kartoglu of WHO/Geneva was asking the question "Isn't it a bit awkward that we tell people first to freeze the icepacks and then thaw them afterwards? Why they cannot just use cold packs?" Spanner of WHO/India agrees with Umit and thinks that we should not talk about defrosted ice-packs but cold waterpacks. Tests show that even icepacks that has been taken from -20degree C and left to thaw for 45min at +20degree C will create negative temperatures in a cold box. Attached is a graph he provides to illustrate the test (top graph). Referring to Bob Davis document in Post 00404E, he also says that top-opening refrigerators are not all coldest in the bottom. For example, the new generation of Vestfrost ILR are, as a matter of fact, coldest at the top third. Finally, during periods of extended power cuts, the ice-lining has to be re-frozen and the temperature goes well beyond 0degree C during this process. In the same attached document, the two other graphs illustrate these points. On follow-up to question 2 asked by James Cheynes in Post 00406E, Anthony Battersby believes that it would be unrealistic to think that we can get rid of the cold chain. Ice (frozen icepacks) is needed at the point of use, both for Measles and BCG that have to be kept cold once reconstituted otherwise may present a danger. Umit Kartoglu reminds us that WHO recommends that reconstituted vaccines must be kept on ice. Keeping them on ice even if contaminated, will slow down the replication of microorganisms such as Staphylocci, therefore reducing the occurrence of adverse events following vaccination. How many times, Anthony asks, does this have to be repeated? Most recently the episode in Algeria (see Signpost 100) is not yet fully explained but unrefrigerated diluents and inappropriate storage after reconstitution are likely culprits. There are other incidents, two in Tajikistan during the last three years, and one in Uzbekistan. In 1995-96, manufacturers were asked to propose a solution to freezing in refrigerators. Then only Electrolux offered a solution for places where the electricity supply is guaranteed. So the problem remains and the freezeproof refrigerator is elusive. He thinks that the likelihood of the quality of electricity improving is remote but he disagrees with John Lloyd's suggestion to switch to solar energy as an alternative power supply. Anthony says that refrigerators are expensive and very difficult to keep operational. He cites the case of Nigeria as an example where no operational solution has yet been successfully implemented. The changeover to solar energy would be thoroughly extensive to bring the price of solar units comparable to regular electric ones and maintenance practical and effective. He doesn't think that hopes for new redesigned vaccines are realistic either. This is a very expensive process for manufacturers (possibly up to $35 million just for one Phase 3 trial) and from discussions he had some years ago, he gathered that market forces at play, where most of revenues come from industrialized countries, will definitely exclude this possibility. Anthony believes that we are being side-tracked by technological issues while the real problem is very weak management. Yes, we do have some technical problems, however there are programmes that manage to handle vaccines safely. We need to concentrate the effort into making management more responsive, by enabling managers to be more responsible. Too many countries have highly centralised managerial systems that leave little decision-making and initiative to local managers. Countries and donors also need to ensure that basic minimal resources are made available for running immunisation services efficiently. This is the crunch ! John Lloyd says "little extra cost" but he thinks there is a need for significant extra cost to give managers and staff sufficient resources to do the job. Maybe someone should compare investments in recurrent costs with those of cold chain failures. This he suspects will highlight the fact that under-investment in running costs is the greatest threat to vaccine safety. ________________________________________________________________ ##text##