Dear Narayana,
Thank you for sharing what you prepared to offer to health workers as job-aid.
I would like to make the following comments. Hope you find them useful:
HEATmarker® is a trademark of Temptime Corporation, and if mentioned it should be mentioned as HEATmarker®.
VVM is a time and temperature integrator, meaning that the color change is the result of the combination of temperature and time together. In your text, you indicate that “on exposing to heat outside the critically set temperature of 2 to 8oC, square irreversibly & gradually turns darker...” sounds like as if VVM does not change color if it is kept at 2 to 8oC. This is not correct, because, even such recommended temperatures have an effect on the VVM. For example, if you keep VVM7 constantly at, say, 5oC for a year, VVM will lose 35% of its shelf-life at the end of the period. Again, if you keep the same VVM7 constantly at 7oC (that is still within the recommended temperature range) for a year, at the end of the period it will lose half of its shelf-life. Of course, what is important here is that we have to explain, that the higher the temperature (not necessarily outside the recommended temperature range) the faster the color change.
In the same sentence, you continue, “merging with the outer ring indirectly indicates discard point matching with loss of potency of the vaccine”. Although in theory, this is correct, we should refrain from referring to potency since it may create an understanding of as if VVM is a potency indicator.
You indicate that “based on heat sensitivity of vaccines, 4 types of VVMs are innovated.” There might be only four types of VVM in the Indian market based on the type and manufacturer of the vaccines, but when it comes to VVM types that are available (and WHO prequalified), today there are 7 types of VVMs.
WHO/PQS prequalified VVMs
Product
|
PQS prequalification date
|
PQS code
|
VVM2
|
30 September 2007
|
E006/001
|
VVM7
|
8 October 2007
|
E006/051
|
VVM11
|
19 June 2018
|
E006/052
|
VVM14
|
15 June 2018
|
E006/054
|
VVM30
|
24 March 2007
|
E006/050
|
VVM250
|
27 March 2019
|
E006/058
|
VVM+250
|
28 March 2019
|
E006/059
|
I would not advocate for the location of VVMs by vaccine type since this could be misleading. Because the location of VVM on the vaccine vial or ampoule depends on its role as a visual cue for the multi-dose vial policy (MDVP). This is clearly explained both in the most recent MDVP document “WHO Policy Statement - Multi-dose vial policy (MDVP): Handling of multi-dose vaccine vials after opening. WHO/IVB/14.07 - retrieved from https://bit.ly/2XC3n6g”, and “Vaccine vial monitor – PQS performance specification, WHO/PQS/E006/IN05.3 -0 retrieved from https://bit.ly/2IZjGlr”. In principle, VVMs are placed either on flip-off caps of a vial or on the neck of an ampoule for vaccines that must be discarded at the end of the session, if opened multi-dose vials of vaccines can be kept up to 28 days then the VVM goes on the label. Why this is important to mention is, because, there could be a liquid vaccine with a VVM on the cap. For example, Cervarix from GSK is a 2-dose liquid presentation, and opened vials of this vaccine should be discarded six hours after opening or at the end of the immunization session, whichever comes first. And to guide the user (with a visual cue) the VVM is affixed on the cap. Other HPV products that are prequalified are from Merck vaccines (Gardasil) and the VVM is on the label. In summary, mentioning the type of vaccine and indicating where the VVM is located is not the best way to explain, best is to mention the visual cue role of the VVM for the MDVP and explain what it means when the VVM is on the label or on the cap of a vial/neck of an ampoule.
Also, I would not make a reference list for vaccines with VVM types. Because, in the future, you may start receiving the same vaccine from another manufacturer and with a different VVM type. Yes, all OPV is with VVM2, but when it comes to other vaccines, the same type of vaccine from different manufacturers may have different VVMs. You will find BCG with both VVM14 and VVM30 produced by different manufacturers. For example, today among 7 WHO prequalified BCG vaccines, Japan BCG and NCIPD products come with VVM7 while all others (from Serum Institute of India, A/J vaccines, GreenSignal Bio Pharma) are with VVM14. Again, today there are 14 IPV products prequalified by the WHO, all products are with VVM7, except the GSK product Poliorix (comes in 1 and 2 doses) is with VVM14. The type of VVM is decided based on the stability characteristics of the vaccine, not by its type.
I liked very much your proposal of “Beneficiaries have right to information; service providers can show the vaccine with useable VVM to the caretakers to gain their confidence for better community participation”. Showing VVMs to caretakers started as a movement in China, championed by the Chinese CDC. In October 2014, Beijing TV local newscast showed the use of the HEATmarker® VVM on the seasonal flu vaccine (http://bit.ly/2ydY26w). In this programme, the head of the Chinese CDC demonstrated the VVM and said that all seasonal flu vaccine for Beijing that year would be coming with VVM attached. He actually asked viewing parents to ask healthcare professionals to show them the VVM. This initiative boosted parents’ confidence with the vaccines and the programme. A similar approach is now being initiated in Kyrgyzstan as part of the priority actions of the HSS2 with Gavi to increase trust in vaccines and immunization services. I would be happy to see and hear that this initiative is spreading to other countries.
Dr Umit Kartoglu
Co-Founder and CEO
Extensio et Progressio
umit@kartoglu.ch and info@extensioetprogressio.ch