Philippines
Pakistan
Inde
Hongrie
Australie
Tétanos
Polio
Coqueluche
Rougeole
Grippe
HIB
Hépatite B
Diphtérie
Gestion de vaccin
Post00239 VACCINE FREEING 06 April 2000
CONTENTS
1. CHANGING VACCINE STORAGE LOWER TEMPERATURE LIMIT FROM 0 TO 2 DEGREES?
2. FREEZE VVMS?
Moderator's note: Corrections:
1. The previous TECHNET Forum post on Tuesday 4 April was Post00238 not
0338 as indicated in the post.Post00237 was incorrectly identified as
Post00337.
2. If you had difficulties downloading the file AideMemoire-
HealthCWaste-3.PDF as referenced in Post00237, WASTE MANAGEMENT + INJECTION
SAFETY, on 30 March 2000, please note that this file is now available for
download. Go to the website
ftp://ftp.acithn.uq.edu.au/Technet/1-ClickHereForTECHNETfiles/
go to the folder "Waste" and click on the file:
AideMemoire-HealthCWaste-3.PDF
or
Send an email to: [[email protected]][email protected][/email]
To get the file - send the message:
get technet AideMemoire-HealthCWaste-3.PDF
____________________________________*______________________________________
1. CHANGING VACCINE STORAGE LOWER TEMPERATURE LIMIT FROM 0 TO 2 DEGREES?
Continued from Post00231, VACCINE FREEZING, 14-15 March 2000.
The current EPI vaccine storage recommendation for refrigerator storage is
one month at 0 'C to +8'C. Other regions of the world and other countries
recommend +2'C, or even +4'C to 8'C. Many manufacturers label their vaccine
vial for storage between 0'C and 10'C.
Mary Catlin, PATH, proposed in Post0218 that, considering the risk of zero
degree storage on HepB - a vaccine coming into wide routine use, that we
try to modify the current recommendation to +2'C to +8'C on the TECHNET
Forum.
The discussions so far have see to the need to raise the lower vaccine
storage temperature limit for vaccines stored in refrigerators, but have
identified some engineering and cost constraints. Extending the proposed
change beyond electric refrigerators appears to be problematical. Other
technology based solutions are not in advanced states of development.
Terry Hart, IT Power India, in Post0226, pointed our that the accuracy of
built in refrigerator thermometers can be in error by as much as 4 degrees,
using existing technologies and called for a new specification for
refrigerator thermometers.
In Post0226, Michel Zaffran, WHO/V&B, raised 3 constraints that need to be
evaluated if we are, in fact, going to change a vaccine storage equipment
specification.
* Anthony Battersby, FBA, discusses this further and concludes that we need
the freeze sensitive VVM.
* See item 2 of this post for discussion of the requirements for a Freeze
Vaccine Vial Monitor.
Contributions, comments and additions please: [[email protected]][email protected][/email]
or use your reply button
___________________________________________________________________________
Date: Wed, 15 Mar 2000 05:49:53 -0500
From: Anthony Battersby
To: Technet Moderator
Subject: Post00231 VACCINE FREEZING
Dear Allan,
Much of the equipment now in use (eg ILRs and RCW42) for storing vaccines
was designed when the specification was +4/+8degC. In addition I have the
impression that most manufacturers specify +2/+8degC on their package
inserts.
The problem with supercooling is that when a supercooled vial is shaken it
immediately changes state and freezes, I have witnessed this phenomenon on
a number of occasions. So it may be OK in the refrigerator but is damaged
as soon as it is taken out to administer.
Paradoxically the countries that use domestic equipment are often those
that are not the poorest. They may have national regulations that require
that the directions on package inserts take precidence over any other
guidance. In my experience in such countries it is difficult to convince a
nurse that she should ignore the package insert. Should the matter ever be
tested in court, for example because a child contracted Hep B after being
immunised with a vaccine damaged by freezing, if storage conditions did not
comply with manufacturers advice, where would liability lie?
At the Washington Technet we were shown a cabinet that could be inserted
into a domestic refrigerator to improve its performance, I think it came
from the Philippines, what happened to it?
Eric et al's manual looks excellent. Are there any data to show by how much
these modifications will improve performance and by how much they reduce
storage capacity? It would be useful to have an example for say an 80L and
200L refrigerator.
Michel is correct, what matters is the temperature of the vaccine and to be
assured of this we need the freeze sensitive VVM. What is the time frame
for this device being available and how high a priority is it being given?
Anthony
____________________________________*______________________________________
2. FREEZE VVMS?
Following the discussions in TECHNET Forum Post00231 VACCINE FREEZING,
14-15 March 2000, the forum received an interesting enquiry from Richard
Hounslea, Loughborough University, UK.
Richard is "working for a company which specializes in time/temperature
indicator technology and is anxious to develop a freeze indicator which
would satisfy the demand highlighted in the forum."
Debra Kristensen, PATH, replies and makes available an old feasibility
analysis on freeze prevention that includes a preliminary product
specification for freeze indicators. Debbie kindly adds her list of
references about freezing in the cold chain, and has indicated that it
needs to be updated.
Thanks are due to Richard and to Debbie for sharing this discussion.
* Technet members should review the old draft specifications with the aim
of getting the indicator that we think will improve vaccine and cold
chain management. Our recent experience with heat sensitive VVMs on oral
polio vaccines should be helpful in specifying a freeze indicator and
bringing it into use.
Contributions, comments and additions please: [[email protected]][email protected][/email]
or use your reply button
___________________________________________________________________________
These files are available for download:
FreezePrevention-References-1.PDF
FreezePreventionFeasibility-4-1996.PDF
Go to the website
ftp://ftp.acithn.uq.edu.au/Technet/1-ClickHereForTECHNETfiles/VAX-Freeze
or Send an email to: [[email protected]][email protected][/email]
To get the file - send the message:
get technet FreezePrevention-References-1.PDF
get technet FreezePreventionFeasibility-4-1996.PDF
___________________________________________________________________________
From: Richard Hounslea
To: "'Technet Moderator'"
Subject: RE: Post00231 VACCINE FREEZING
Date: Fri, 24 Mar 2000 10:52:49 -0000
Dear Allan,
I write to you in reference to the growing need for a Vaccine Vial Freeze
Indicator. I am working for a company which specialises in time/temperature
indicator technology and is anxious to develop a freeze indicator which
would satisfy the demand highlighted in the forum. I would be most grateful
if you could clarify any of the following;
1. The different types of vaccine, both current and predicted, that the
indicator would be required to monitor. As far as I can ascertain DPT,
HepB, TT and DT are of most concern. Are there any others?
2. An estimate of the volume of indicators required.
3. Whether different vaccines will require different performance
characteristics from the indicator (time/temp, threshold etc.)
4. Requirements for the indicator, for example, interpretation
considerations (I am assuming that because the indicator will be 'dual
threshold' it will need to combine two different indicators, perhaps even
requiring different technologies).
5. Requirements for the indicator in terms of size, attachment to the vial,
cost etc.
6. The integration of the monitor with other forms of indicator which may
be used inside a refrigerator.
Any information that you could provide which will enable us to develop a
completely satisfactory indicator would be gratefully received. I look
forward to your reply and the opportunity to discuss this with you further.
Richard Hounslea
Loughborough University
United Kingdom
----
From: Allan Bass [mailto:[email protected]]
Sent: Sunday, March 26, 2000 3:23 PM
To: [[email protected]][email protected][/email]; Kristensen, Debra
Cc: Technet Moderator
Subject: Freeze VVMs : Fwd: RE: Post00231 VACCINE FREEZING
Dear Hans and Debbie,
This came in on the weekend. A time - temperature indicators technology
company expressed an interest in Freeze VVMs following Technet Post00231 on
14-15 March 2000.
I have sent Richard the E6/IN.3 spec appended to the end of this email and
referred him to the VVM material in the WHO V&B Document Centre.
* We need - (or do we have some unpublished spec?) a Freeze VVM spec -
including label placement & max dimensions and possibly
overlay/compatibility with the existing heat VVM.
What Action next?
regards,
allan
----
E6: Temperature monitoring devices
12 Equipment performance specifications and test procedures
FREEZEWATCH INDICATOR, IRREVERSIBLE
Specification reference: E6/IN.3
Applies to procedures: E6/PROC/3
Date of last revision: 1 January 1998
Temperature threshold:
-5?C, irreversible colour change or
0?C, irreversible colour change
Time/temperature function: None
Features: Colour spot change at threshold temperature
Application: Packed with adsorbed vaccines (DT, DTP, TT and Hepatitis) to
warn of exposure to temperatures below -6.5?C for the -5?C model and -1?C
for the 0?C model.
----
From: "Kristensen, Debra"
To: Technet Moderator
Subject: RE: Freeze VVMs : Fwd: RE: Post00231 VACCINE FREEZING
Date: Mon, 27 Mar 2000 11:57:57 -0800
Allan:
Thanks for the information. I am enclosing 2 documents that might be useful
to share with Richard:
1) An old feasibility analysis on freeze prevention that includes a
preliminary product specification for freeze indicators.
2) My list of references about freezing in the cold chain.
Regarding market size, the following information may help. For the year
2000, UNICEF will procure the following quantities of freeze-sensitive
vaccines:
DT = 115,000 vials
DTP = 9 million vials
Td = 110,000 vials
TT = 10 million vials
Soon we will also know about the quantities of hepatitis B vaccine that the
Global Fund intends to purchase in late 2000/early 2001.
Does someone have information on the quantity of hepatitis B vaccine that
PAHO is purchasing in 2000?
Finally, I would be willing to have a discussion with Richard about the
potential for product development collaboration between PATH and the
university.
All the best,
Debbie
---
From: Richard Hounslea
To: "Allan Bass (E-mail)"
Subject: Post 00231 VACCINE FREEZING
Date: Wed, 29 Mar 2000 10:50:39 +0100
Dear Allan,
Thank-you for you reply to my e-mail concerning specifications and
requirements for the Freeze VVM. The information I received from Debra
Kristensen was most useful. There are however a couple of points which I
would be most grateful if you could clarify.
In the feasibility analysis which Debra e-mailed to you, point '3' of the
section 'Proposed Technology' states, "The indicator colour must not cause
confusion with EPI colour codes or VVMs on vaccine vials". I have searched
through the Equipment Performance Specifications and Test Procedures
document and have found no reference to 'colour codes' as such, only the
specifications concerning the rate at which the heat VVMs change colour
(start-points, end-points etc). Perhaps they are the same thing? Obviously
if would be of no use to you if we manufactured a Freeze VVM which used the
wrong colours!
I would also welcome your thoughts on the time lag required for the
indicator to activate and the rate at which the "conversion" should occur".
This was highlighted in point '1' of the same section of the feasibility
study.
I realise that it may be a little too early to clarify all of the specs and
requirements, but any further information would be most appreciated. I look
forward to hearing from you in due course.
Richard Hounslea
Loughborough University
UK
----
From: Allan Bass [mailto:[email protected]]
Sent: Sunday, April 02, 2000 10:14 PM
To: Richard Hounslea
Cc: Kristensen, Debra; [[email protected]][email protected][/email]
Subject: Re: Post 00231 VACCINE FREEZING
Dear Richard,
The EPI vaccine colour codes refer to plastic caps, Au bands, and labels on
multidose vials - i.e. "Orange" for Measles vaccine, and so on. I cannot
put my hands on the colour code details at the moment - but will them
locate soon [As a quick check - I note that they do not appear in the WHO
model procurement specifications for vaccines. The VVM colors that I'm
aware of are white and shades of blue and purple.
Your second question on time lag is a good one. You might check with Debbie
Kristensen at PATH. Path worked for more than 15 years on the development
of the heat/time VVMs and will have a lot of usability data from the many
field trials. Personally - I would think something that tracked the phase
change in the vaccine in the vial would be appropriate.
I hope that this helps. Debbie is the best person to
discuss these issues with. Please keep me informed.
regards,
allan
----
From: "Kristensen, Debra"
To: Richard Hounslea
Cc: [[email protected]][email protected][/email]
Subject: RE: Post 00231 VACCINE FREEZING
Date: Wed, 5 Apr 2000 13:54:52 -0700
Dear Richard:
The draft specifications I sent were a few years old. I believe that WHO
has since dropped the EPI colour codes. It was my understanding that the
colours (e.g., PMS 327 Green for TT, PMS 287 Blue for hepatitis B
vaccine...) were incorporated onto the paper label on the vial. But this is
likely to be a non-issue now. Perhaps Allan will locate the definitive
answer on this.
The only VVMs currently available are from LifeLines and they change from
light purple (nearly white) to dark purple. However, WHO does not specify a
color for VVMs. They only specify that there must be a shade change from
light to dark with heat exposure, but no change in hue. I enclose a copy of
WHO's VVM specifications.
The time lag is tricky because current recommended storage temperatures for
vaccine are 0-8 degrees C and hepatitis B vaccine freezes at approximately
-0.5 degrees C. Also, we must take into account the facts that the
temperature outside of a glass vial differs from that inside and that
smaller quantities of vaccine (i.e., single dose vials) will freeze faster.
We could conduct studies on the time taken for a specific quantity of a
specific brand of vaccine to freeze and/or to lose potency, but this may
not be necessary. We want the indicator to be conservative so that it errs
on the safe side, but not so conservative so that vaccine is wasted
unnecessarily. It would be ideal if the indicator could be customized to
the freezing point of the vaccine, but this might increase the cost. The
accuracy of the indicator becomes very important in setting the conversion
point. For example, If the accuracy is +/- 1 degree C we may need to set
the conversion point at 0.5 degrees C for hepatitis B vaccine to be safe
and this is within normal storage temperatures.
At this point, it might be best to begin a dialogue about the capabilities
of your technology and how it might meet the needs as currently defined.
Please let me know if a meeting would be useful. I may be in Europe later
this month and we always welcome visitors to Seattle. We could also sign a
confidentiality agreement, if necessary.
All the best,
Debbie Kristensen
Technical Officer
Program for Appropriate Technology in Health (PATH)
4 Nickerson Street, Seattle, WA 98109-1699 USA
Telephone: (206) 285-3500; Fax (206) 285-6619
E-Mail: [[email protected]][email protected][/email]; PATH Web Site: http://www.path.org
___________________________________________________________________________
Feasibility Analysis: Preventing Delivery of Vaccine Damaged by Freezing
April 1996
Extracts
___________________________________________________________________________
STATEMENT OF PROBLEM TO BE ADDRESSED
Certain vaccines are more at risk from loss of potency due to freezing than
to heat exposure. These vaccines include diphtheria, pertussis, and tetanus
(DPT), diphtheria toxoid (Dt), tetanus and diphtheria toxoid (Td), tetanus
toxoid (TT), and hepatitis B vaccine. In addition, most or all of the
vaccines which may come into the EPI in the future, e.g., pneumococcal and
hemophilus influenza vaccines are expected to be freeze-sensitive. Freezing
can totally and irreversibly damage the efficacy of these vaccines and
increase the risk of side effects. Freezing of vaccines can occur when
vials are exposed to cold during:
* transport in cold boxes with ice or ice packs;
* transport as air cargo;
* storage or transport in areas with low ambient temperatures; or
* storage in cold rooms or refrigerators (especially ice-lined and domestic
refrigerators) that are set at inappropriately low temperatures or have
nonuniform temperatures within, e.g., cold spots near the freezer
compartment.
SITUATION ANALYSIS
Low vaccine efficacy rates are often attributed to vaccine damage due to
freezing. For example, a recent check on the efficacy of TT supplied by
UNICEF and transported through the cold chain to Punjab, Pakistan, showed
vaccine efficacy rates as low as 24 percent in one district.
Studies of the cold chain, i.e., the systems for transporting and storing
vaccines from the place of manufacture to the place of administration, have
revealed "breaks" in the cold chain during which vaccines were
inadvertently frozen. A 1987-88 study published in the Bulletin of the
World Health Organization revealed that in Hungary up to 38 percent of DPT
was exposed to below-freezing temperatures in the winter. A 1990 study in
Australia found that 47.5 percent of tagged hepatitis B vaccine vials were
exposed to -3?C or less the majority of them during storage in health
facilities.
----
PROPOSED TECHNOLOGY
Preliminary freeze indicator specifications:
1. The indicator should exhibit an irreversible, easy-to-interpret, visual
response after exposure to the freezing temperature (or a slightly higher
temperature) of the vaccine for which it is being used, e.g., -5?C for DPT,
DT, and TT and -0.5?C for hepatitis B vaccine. The length of time of
exposure at the freezing temperature prior to indicator "conversion" needs
to be established with assistance from WHO.
2. The indicator should be small so that it can be used on individual
vaccine vials. Ideally, it should be a flat device with a maximum size of
one square centimeter to avoid obscuring existing labeling information. The
indicator could potentially be detachable and reusable since its useful
life spans from point of manufacture until frozen. However, the indicators
would need to be collected from end-users and returned to vaccine
manufacturers - a task that may be feasible in situations of national
vaccine distribution.
3. The indicator color must not cause confusion with EPI color codes or
VVMs on vaccine vials.
4. The indicator must be low cost. As with VVMs, the additional cost of a
vaccine vial due to the indicator must not exceed the cost of a single dose
of vaccine in a 10-dose vial.
5. The indicator must be of a configuration that permits labeling onto
vaccine containers at the vaccine production sites without adversely
affecting production line speeds.
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