POST 00448E : USE OF VVMs ON ALL VACCINES

POST 00448E : USE OF VVMs ON ALL VACCINES Follow-up on Post 00446E 4 May 2002 _________________________________________________ Some more comments and questions about the use of VVMs were received. First from G R Baru, Project Officer (Cold Chain) at the UNICEF/India country office (mailto:[log in to unmask]) _________________________________________________ My comments on Dr Jayaprakash’s observation on VVM of OPV is that beside high ambient temperature, sustained exposure to vaccine even at lower temperature is a major a factor to bring change in VVM status. I took one vial of OPV-VVM stage-2 from one of the PHCs in Bihar (India) which reached stage-3 within 3 hours at ambient temperature whereas an OPV vial which I took from another PHC at the same stage-2 changed its color to stage-3 after 8 hours. This appears that the latter one had more cumulative effect of higher temperature. During my recent visit to Iraq for strengthening of cold chain maintenance, I also observed that VVM changes color from stage-2 to 3 even during storage in kerosene oil refrigerators. It could be due to the reason that kerosene refrigerators normally do not maintain 2-8°C temperature when ambient temperature is above 45°C thereby exposing vaccines at higher temperature for a sustained duration. We do not have any experience with VVMs on measles vaccine as it is yet to be introduced in India. _________________________________________________ Bal Ram Bhui from the CORE Group PEI, Nepal (mailto:[log in to unmask]) also contributes the following. _________________________________________________ While the people in immunization business are excited and eager to see all vaccine with VVMs, the concerned manufacturers also need to look at the integrity of labels on the vaccine vials. Our experience with OPV VVMs suggest that the label can come off the vials. The melting of ice on the icepack and frost produced inside the cold box made vials sufficiently wet to allow labels to come off even with normal handling of vials. I think this should be a serious issue for researchers, manufacturers and health workers when we want to use VVM as a management tool. __________________________________________________ Ümit Kartoglu from WHO (mailto:[log in to unmask]) shares these comments and answers to questions raised above. __________________________________________________ The observation by Dr. Jayaprakash is quite interesting and shows how the informed choice could be taken. This also underlines the important fact that VVM is the ONLY tool that is available at all times during distribution and storage as well as when the vaccine is administered, indicating whether the vaccine has been exposed to a combination of excessive heat over time and whether it is likely to have been damaged. However, we should also keep in mind that such experiments may produce confusing results. VVM reaction rate is not only affected by heat exposure, but also by UV light. When a vial is taken out for such an experiment, the reaction rate will depend on the combined affect of the ambient temperature and the UV light exposure. This is why all VVM validation tests (and the tests conducted by LifeLines for lot release of each batch) are conducted in temperature-controlled water baths with NO lights. The problem of vaccine labels coming off as indicated by Bal Ram Bhui from Nepal is not directly linked with VVM. UNICEF and GAVI tenders require "water-resistant" adhesive for the vaccine labels. This is listed among the "minimum requirements" for vaccines to be procured by UNICEF: QUOTE "Vaccine vial labels shall be affixed with water-resistant adhesive so that the labels do not become loose or fall off." END QUOTE Regarding complaints, we [WHO] need to know the vaccine manufacturer and the type of presentation in question. For such complaints, we encourage colleagues to contact directly Dr. Nora Dellepiane (mailto:[log in to unmask] ) at WHO-HQ in Geneva. One way of preventing vials getting wet is to use ziplock bags. This can be used especially with vaccines intended to be used in subsequent sessions within the multi-dose vial policy (MDVP). Vials submerged in water cannot and should not be used in subsequent sessions. Using ziplock bags can also help in facilitating this condition for MDVP implementation. Ziplock bags are available from UNICEF Supply Division: S0521425, Envelope, plastic, 10x15cm, pkt of 100, $0.41 PER PKT OF 100. Even if they are cheap, volume-wise they are quite small and cannot accommodate many vials. Maybe UNICEF SD could purchase bigger sizes if required. ----------------------------------------------------------------------------- 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. 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