POST 00864E : COMBINATION VACCINES, LYOPHILIZED VACCINES, DILUENTS AND VVMS

POST 00864E : COMBINATION VACCINES, LYOPHILIZED VACCINES, DILUENTS AND VVMS Follow-up on Posts 00847E, 00852E, 00855E, 00858E and 00860E 7 December 2005 _____________________________________ This posting opens on a short suggestion by Mohammad Nazih Abdallah (mailto:[email protected]) from the United Arab Emirates, followed by contributions from Casimir Manengo (mailto:[email protected]) from Chad and AbdulQuadir Olawale Oni (mailto:[email protected]) from Nigeria. _____________________________________ Dear Moderator I think one solution for this issue is to use the single dose combination (combo pack) regards Mohd N. A. Mohammad Nazih Abdallah, MPH Public Health Specialist EPI / Vaccines Cold Chain & Quality Control Central Department of Preventive Medicine Ministry of Health - Abu Dhabi ---------------------------------------- I read very carefully all the elements of the debate on the use of multidose vaccines mixing a lyophilised vaccine with 1 or 2 other vaccines used as diluents, and the use of VVM. In my opinion, there are two levels of debates: Level 1: Preparation and production of vaccines -Is there a preservative agent which can warrant with safety, the stability of the mixture of lyophilised and liquid vaccines over several days? -Where should the reconstituted vaccine be kept? In the lyophilised vaccine vial or in the vial of the liquid vaccine used as diluent? -Will the VVM placed on the lyophilised vaccine vial take into account the thermo-chemical reactions after reconstitution with the diluent vaccine? - What quality control system will we have at country level? -What is the capacity and rhythm of substitution/replacement of previous vaccines presentations by new ones, to avoid simultaneous use of the two. This could bring about confusion at storage and utilization level in countries' vaccination programmes. Level 2: Vaccination programme and health services (vaccination) - Requirement: Accelerate the new vaccines introduction process, with major problems of capacity to absorb new vaccines and adaptation to rapid change. - Risk of wrong handling by health personnel: reconstituting vaccine with the wrong diluent or with different expiry dates. - Problems of arrangement of vaccines in the refrigerator, especially reconstituted vaccines. - Confusion in applying vaccines utilization guidelines with risks of opting for the solution of least effort, i.e. discard all reconstituted vaccines or keep them all beyond recommended dates. - Difficulties in interpreting the right VVM. Suggestions : 1. Production of 5-10 doses lyophilised and diluent vaccines in order to reduce the risk of keeping opened vials in the refrigerator 2. The VVM must indicate the state of the vaccine from the time of its reconstitution in the lyophilized vacine vial, and not the diluent vaccine vial. 3. Place the VVM on the lyophilised vaccine vial and not on the diluent vaccine vial. 4. Ensure that in the process of new vaccine introduction, old vaccine presentations are replaced with new ones as they are introduced. This is my modest contributions to the debate, which I hope will yield results disseminated to each and every one of us. With my collaboration. Casimir Manengo Dr Casimir M. MO/Surv. TCHAD ------------------------------- Dear Michel I'll like to make the following submissions on the above issue: Since combined pentavalent DTP-HepB-Hib is not commercially available yet, the prospect of addition of DTP-HepB and freeze dried Hib at point of use would have to continue to respect "discard at end of session or after 6 hrs which ever comes first" recommendation (at the risk of high wastage rate of an expensive vaccine except the presentation stays at the current 2 dose presentation) for the following reasons: VVM on any of the individual vaccines is meant for them only and would only indicate their respective heat exposure with time profile. If added together at point of use i.e. DTPHepB being used as the diluent for Hib, there should be no justification for using the VVM of either of the initial products to monitor the addition (i.e. DTPHepB + Hib). It is most appropriate to use the heat exposure with time profile of the addition (i.e. after due accelerated stability tests) rather than the initial individual products. Nonetheless, the plausible question of using a more fastidious VVM profile to monitor the "new product" i.e. the addition is also not tenable because this would not be giving a fair indicator of the heat exposure profile with time of the addition and may lead to erroneous discard of vaccine and thus wastage which is the main concern of the treatise. This equally applies to situation where the VVM of the most heat sensitive of the two is used. As a follow up to the foregoing, in regulatory parlance, the addition DTPHepB+Hib needs the approval of the regulatory authority (i.e. initial regulatory application should state that the individual products would be added before use and is so approved). What this means is that the approved DTPHepB from particular manufacturer may be approved to be used as a diluent for the Hib vaccine of same manufacturer (or another specified manufacturer) but not just any manufacturer's DTPHepB or Hib. This has an implication in the event of a need to resolve an AEFI after administration of the "addition". In this case there may be difficulty in identifying the responsible vaccine or the suspect product- the products before addition or the "new product" after addition? Since VVM plays a crucial role in heat exposure indicator of vaccines and measure of good vaccine handling, it is essential that precise VVM to tested products be used to facilitate such AEFI resolution. Hence regulatory considerations have strong implications on which VVM can or may not be used. Hence it would be most inappropriate to use the VVM of the DTP-HepB added with Hib on the label of either of them prior to their addition. Bearing in mind the concerns you have raised in your initial submissions, I would conclude as follows: A. "Discard policy after 6 hours or at the end of session whichever comes first" continues to apply to the addition without a new VVM to the 'addition' as obtainable for other lyophilised vaccines after dilution; B. If we must increase the dose presentation it would have to be for programmes with "matured vaccine management profile" (with record of acceptable wastage rate) and a maximum of 5 dose presentation. Finally, combined DTP-HepB, combined DTP-Hib and combined pentavalent (DTP injectable polio and Hib) vaccines are in commercial circulation (Sanofi Aventis, GSK for example). Hence their presence gives hope of a combo pentavalent DTP-HepB-Hib vaccine rather than an addition. ONI AbdulQuadir Olawale Ago-Taylor, Odo Ona, Ibadan. ______________________________________________________________________________ _________________________ Visit the TECHNET21 Website at http://www.technet21.org You will find instructions to subscribe, a direct access to archives, links to reference documents and other features. ______________________________________________________________________________ To UNSUBSCRIBE, send a message to : mailto:[email protected] Leave the subject area BLANK In the message body, write unsubscribe TECHNET21E ______________________________________________________________________________ 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. 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