Post0214 VACCINE FREEZING 07 January 2000
CONTENTS
1. COMMENTS: ALERT: FROST-FREE REFRIGERATORS IN THE COLD CHAIN
2. INTRODUCTION OF FREEZE SENSITIVE VACCINES INTO THE EXISTING COLD CHAIN
3. TECHNET RECOMMENDATIONS ON CC EQUIPMENT WITH LOW TEMPERATURE PROTECTION
Contributions to: [[email protected]][email protected][/email] or use your reply button!
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Welcome to the TECHNET Internet Forum for the new Century. Technet'99 in
Harare, 6-10 December 1999 was our 7th, our largest and most diverse to
date. For those unable to attend Technet'99 there will be a lot to read and
discuss as well as news on developments in logistics for health and the
Technet itself. As the draft documents come to hand they will be posted to
the TECHNET Forum or made available for download.
Participants comments on the meeting and additional feedback to those
unable to attend will be appreciated.
During the moderator travel and summer break no TECHNET Forum editions were
posted. Please join us in catching up and expanding our discussions.
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1. COMMENTS: ALERT: FROST-FREE REFRIGERATORS IN THE COLD CHAIN
In Post0212, VACCINES & COLD CHAIN, 26 November 1999, TECHNET Forum posted:
ALERT: FROST-FREE REFRIGERATORS IN THE COLD CHAIN, a warning from Anthony
Battersby, FBA Health System Analysts, on the vaccine freezing conditions
in "frost free" and "multi-flow" refrigerators and called for accelerated
efforts to develop and implement vaccine vial freeze indicators.
Both the WHO and vaccine manufacturers warn against the freezing of DTP,
DT, Td, TT, Hb, HIB and other liquid vaccines. Recent data suggests that
temperatures below 0'C will damage pertussis vaccine.
In today's posting Nan Miller, CDC-THS, responds to Anthony's alert,
supporting the need for freeze sensitive Vaccine Vial Monitors.
Nan points out the very important role of modified domestic equipment and
good management in minimising vaccine freezing.
Action, comments and additions please: [[email protected]][email protected][/email]
or use your reply button
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Moderators Note: See: Miller N., Harris M., Are childhood immunization
programs in Australia at risk? Investigation of the cold chain in the
Northern Territory. Bull World Health Ogr, 1994;72(3):401-8
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From: [[email protected]][email protected][/email]
To: [[email protected]][email protected][/email]"
Subject: Frost Free Refrigerators
Date: Mon, 29 Nov 1999 11:53:16 +0930
I would like to comment on the following item.
Post0212 VACCINES & COLD CHAIN 26 November 1999
1. ALERT: FROST-FREE REFRIGERATORS IN THE COLD CHAIN
Although I concur with Anthony regarding the need for VVM for all vaccines,
I feel his warning with regard to frost free refrigerators is extreme. In
my 10 year experience with vaccine cold chain management in the Northern
Territory of Australia, frost free domestic refrigerators are very
effective for the safe storage of vaccines with only minor modifications
(i.e. thermal lag, appropriate storage patterns [loading], daily
temperature
monitoring) and good management.
Although freezing of vaccines remains a concern we have reduced losses due
to freezing from over 47% to less than 5% during storage using only
modified, frost free refrigerators.
Nan Miller
Centre for Disease Control
Territory Health Services
DARWIN NORTHERN TERRITORY
AUSTRALIA
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To: [[email protected]][email protected][/email]
From: [[email protected]][email protected][/email]
Date: 30 November 1999
Subject: Frost Free Refrigerators
Dear Nan,
Thanks for your contribution to TECHNET.
It would be helpful if you discuss the modifications made to the frost free
refrigerators - particularly since you have reduced losses due to vaccine
freezing to such a great extent.
regards and thanks,
allan
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2. INTRODUCTION OF FREEZE SENSITIVE VACCINES INTO THE EXISTING COLD CHAIN
Due to the unavoidable absence of a number of colleagues as well as a clear
shortage of time at Technet'99 in Harare, our discussions relating to the
vaccine cold chain during the meeting were limited.
Soren Spanner, WHO/SEARO, raises the fact that existing cold chain
equipment meeting the agreed WHO/UNICEF/EPI cold chain specifications
does not provide low temperature protection. This current equipment will
continue to freeze damage both the routine vaccines DTP and TT, but with
the wider introduction of Hepatitis-B and Hib, among other new vaccines,
this equipment will freeze large quantities of the newer vaccines. The
cost to national immunization programs in wasted activity, resources,
disease and credibility will not be negligible.
While this is an issue that should have been discussed at Technet'99, the
need for action remains.
Beginning with the first TECHNET Consultation in 1990 in Cyprus we
have been discussing Diphtheria, Tetanus and Pertussis vaccine damage
due to freezing. More recently hepatitis-B vaccine and other new
vaccines have entered national immunizations programs and vaccine
freeze damage has been of increasing concern.
In the 1998 TECHNET Consultation in Copenhagen, data from European,
Central Asian and tropical countries were presented which demonstrated that
low temperature events lasting longer than 2 hours occur with with some
frequency in vaccine refrigerators in both temperate and tropical climates.
The WHO/EPI Recommendation has long been that "one freezing event is
sufficient to damage diphtheria, pertussis and tetanus vaccines and
they should not be used". You can add Hep-B and Hib too. DPT vaccine has a
reported freezing/melting point of around -3'C to -4'C, and HepB at -0.5'C.
More recent data suggests that super cooling may also damage pertussis
vaccine.
Soren promises to post recently analysed long term data on low temperature
exposure under various operational conditions. A preview seen at the
Technet meeting was very convincing.
* Are 0'C STOPWatch indicators or 0'C Freezewatch indicators always used
where freeze sensitive vaccines are stored. Are low temperature cut-outs
installed in all vaccine refrigerators?
* NO!
Current reports from the field suggest that a lot of cold chain equipment
in many countries is in bad condition or not functional and will need
replacement. Should we do something now or leave vaccine effectiveness to
the next equipment replacement cycle?
* Low temperature protection for vaccines is not an option.
* What should we do?
Action, comments and additions please: [[email protected]][email protected][/email]
or use your reply button
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From: Soren Spanner"
To: [[email protected]][email protected][/email]
Date: Thu, 16 Dec 1999 12:21:12 +0530
Hi Allan,
I do not think the Cold Chain got as much attention [at the Technet
meeting] as needed.
And I do think that much HEP.B vaccine will be (are being) frozen in the
cold chain. See my comments below.
best regards,
soren
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Introduction of "freeze sensitive vaccines" to the existing cold chain.
We have all seen it, frozen DPT & TT in the existing cold chain, it has
been discussed again and again, not much action has been taken.
Now we are introducing even more "freeze sensitive" and expensive vaccines,
namely Hep B.
I fear that much of this vaccine will be frozen and spoiled before reaching
the child.
I recommend that refrigerators for the cold chain are made in such a way
that subzero temperatures, in the vaccine compartment, be made impossible
(revision of specifications).
Having the VVM for polio vaccine we are able to monitor the status of
the "heat sensitive" vaccine.
So far, there is no monitor for the new "cold sensitive" vaccines.
What is the greatest risk to the vaccine today:
Is it "boiling" or "freezing"?
Vaccines sensitive to cold are very sensitive, i.e. once frozen they are
spoiled.
Soren Spanner
Technical Officer
WHO-SEARO
New Delhi
India
Phone: +91 98100 59757
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3. TECHNET RECOMMENDATIONS ON CC EQUIPMENT WITH LOW TEMPERATURE PROTECTION
From the Technet'98, Copenhagen meeting report:
Recommendation 7. Recognizing that adsorbed vaccines are exposed to
freezing damage in winter in temperate and cold climates, it is recommended
that the TECHNET proceed with the development of Low Temperature Protected
vaccine storage and transport equipment specifications, test procedures,
and guidelines.
--- AND ---
5. COLD CHAIN OF THE FUTURE
PERFORMANCE SPECIFICATIONS FOR REFRIGERATORS
5.1 Current standards for vaccine storage will not be changed.
However, WHO will modify the refrigerator Standard Performance
Specifications and Test Procedures to present requirements for two to three
climatic zones and for three zones of electrical power reliability. The
modified requirements will be sent to all listed equipment suppliers and
the next edition of the Product Information Sheets will be modified to
indicate for which zone(s) each refrigerator is suitable.
5.2 Guidelines will be prepared on the selection and use of domestic
refrigerators for vaccine storage. The guide will include instructions on
the measures (modification kit) to be taken by the user to maximise the
performance of such refrigerators and maintain 0degree C to +8degree C storage
temperatures in ambient temperature ranges set after the review of
environmental databases is completed.
SPECIFICATION FOR LOW TEMPERATURE PROTECTED REFRIGERATORS
* Low Temperature Protected refrigerators for use in temperate and
cold climates will meet WHO/EPI vaccine storage standards (0degree C to
+8degree C) in an ambient temperature of +32degree C to -10degree C.
* The refrigerators will maintain 0degree C to +8degree C in a diurnal operating
range of +15degree C and -10degree C
* Other performance characteristics will be consistent with existing
equipment specifications. It is desirable that the specified
operating ambient temperature range be consistent with the
performance testing range set by the working group on the cold chain
of the future for less hot climatic zones.
PROPOSED PROCESS:
* Proposed operating temperature ranges for temperate and colder
climates by reference to global environmental climate temperature
databases will be confirmed (IT Power/WHO). This will also lead to a
more explicit definition of the geographical extent of the colder
populated temperate and colder zones.
* WHO/GPV will develop, draft and circulate final specifications to
the TECHNET working group on low temperature protection by the end of
June 1998.
* Guidelines will be drafted and circulated for comments to the TECHNET
LTP working group by the end of April 1998 (IT Power).
* Low Temperature Protected vaccine storage equipment will be incorporated
in the equipment performance specifications and test procedures manual. All
recommended vaccine storage and transport equipment for the temperate and
cold climate zone will be expected to comply with this specification.
* Manufacturers will be invited to produce equipment to Low Temperature
Protection specifications. Equipment meeting the LTP specifications will be
included in the PIS.
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