I would like to affirm John Lloyd’s suggestion to use WHO’s Temperature sensitivity of vaccines as a reference. Furthermore, PATH has recently mapped out stability data of licensed vaccines and this is also a useful guide and should be available on Technet resources.
Stability-table-LICENSED-FINAL-updated-8212012.pdf
To complement John’s statements below:
• ]WHO knows of no body of scientific evidence to assert the phenomena of ‘thermal assault’ on vaccines as queried in this posting
• Standard WHO recommendations have always been that the diluent, if not stored in the cold chain at +2ºC - +8ºC, should be cooled to that temperature range for several hours prior to use for reconstitution -- preferably for 24 hours or for a period of time sufficient to ensure that the vaccine and diluent are both at temperatures between+2ºC - +8ºC when they are reconstituted . This was because some of the vaccines to be reconstituted, especially live attenuated virus vaccines, were not heat stable and in fact had only a limited stability when reconstituted, even when kept at +2ºC - +8ºC. Current formulations of these types of vaccines, but not all, are more stable than in previous years. Vaccinators are advised to follow manufacturer’s instructions regarding cooling prior to reconstitution.
• Reconstituted vaccines may become contaminated with staphylococcus and other organisms from improper handling. To avoid this, in line with the Multi-dose Vial Policy, reconstituted vaccines must be kept cooled and must be discarded at the end of the immunization session, or within six hours after opening, whichever comes first.
• At service delivery level, it is recommended that most vaccines be kept at between +2ºC to +8ºC. The VVM (if it is attached) indicates whether the individual vial has been exposed to cumulative levels of heat over time such that the vaccine’s potency may be compromised and thus its stability diminished. This means that vaccines can be used reliably if the VVM has not passed its discard point, even if there have been short breaks in the cold chain, and provided that the expiry date has not passed. It is therefore not dependent on how many times the vial is taken out of the chain. However, it is important to note that current VVMs do not necessarily reflect short ‘peak’ exposures of vaccines to extremely high temperatures (i.e., 45ºC or above). Care should be taken to avoid these situations, especially during transport.
• WHO offers a range of video resources available that explain how VVMs work and how to interpret them properly. I have listed them at the end of the posting.
• WHO recommends the use of baskets in ILRs to address the concerns as mentioned in the post, and encourages the use of continuous temperature monitoring devices (digital) to adequately monitor excursions outside the recommended temperature ranges
• The global guidance on the Multi-Dose Vial Policy and the Immunization in Practice modules are currently being revised by WHO and will be issued this later year.
Diana Chang Blanc
Team Manager, Programme Operations
WHO Geneva, EPI
How does a VVM work? by Denis Maire
https://vimeo.com/58747176
Denis Maire summarizes the technical characteristics of VVMs and explains how they work.
Interpretation of VVM in relation to other temperature monitoring devices by Umit Kartoglu
https://vimeo.com/58156915
Umit Kartoglu reviews temperature monitoring devices used in a typical vaccine cold chain and analyses how the readings relate to each other when there are more than one device at a particular point. This analysis is done from the VVM perspective.
Using VVM as a stock management tool by Umit Kartoglu
https://vimeo.com/58161022
Umit Kartoglu
Umit Kartoglu reviews the requirements for product arrival, storage and dispatch and analyses the role of VVM in effective stock management for each step. Special emphasis is given to the relation of VVM and expiry date in illustrating how VVM over-rules earliest expiry first out principle.
Vaccines beyond the cold chain by Simona Zipursky
https://vimeo.com/58148555
Simona Zipursky reviews the studies on taking vaccines beyond the cold chain all published in peer-review journals and comments on how VVMs could be instrumental in these operations.
VVMs getting smarter by Umit Kartoglu
https://vimeo.com/58161023
Umit Kartoglu reviews the recent changes in integrity and location of VVMs and the new message VVM is giving whether a vial containing multi-dose vaccine following opening can be kept for a subsequent session or not.
VVM use at the most periphery by Serge Ganivet
https://vimeo.com/58680045
Serge Ganivet reviews the VVM use at the most periphery through different examples and brings new perspectives on how to make best decisions based on the expiry and VVM readings.