POST 00568E : FREEZING OF SINGLE-DOSE VACCINE PRESENTATIONS

POST 00568E : FREEZING OF SINGLE-DOSE VACCINE PRESENTATIONS 30 May 2003 _____________________________________________ This posting is an exchange between a few members on the above mentioned topic. It started with a question by Girindre Beeharry (mailto:[log in to unmask]) relayed by Robert Steinglass (mailto:[log in to unmask]) to other colleagues. Girindre's question is followed by short replies from John Lloyd (mailto:[log in to unmask]) and Allan Bass (mailto:[log in to unmask]) This is interesting and members would surely appreciate having more details on this issue, for example experiments that John is referring to. It would also interest readers to know the implications on cold chain and vaccine management. _____________________________________________ I have tried to ask around whether it is any easier/harder for a single-dose vial/Uniject to freeze than it is for a multi-dose vial and was told that we could not answer this question without a study since there are multiple factors involved: thickness of material, insulating capability of material, outer packaging, etc. Thanks again -- Girin ___________________________________ Multiple factors yes, but Uniject would be less prone to supercooling because of the flexibility of the pouch (supercooling is pressure dependent). Mind you, our experiments froze Uniject HBV without any problem and produced perfect shake test results too. All the best, John ____________________________________ On the freezing in Uniject or other monodose presentation - one dose of 0.5 ml water based vaccine will freeze a lot faster than 10 ml - say almost 20 times faster - whatever the modification introduced by other factors. regards and best, Allan ______________________________________________________________________________ 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:[log in to unmask] 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. 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) ______________________________________________________________________________