1. Wendy Prosser
  2. équipement de la chaîne du froid
  3. vendredi 14 octobre 2016

Does anyone have experience with vaccine passive storage devices in the field? We are piloting the PQS pre-qualified Arktek device in three rural health centers. By design, the device maintains a temperature range between 0°C and 10°C which will not freeze the vaccines so should not pose any risk to the potency of the vaccines. We are seeing some unease from health workers and EPI managers, though, who are concerned that vaccines would be out of the 2°C – 8°C range and at risk of freezing, even though all the evidence shows this type of passive storage device will not freeze vaccines when following proper procedures for conditioning the ice.

On the one hand, this reaction from the health workers speaks to the success of training and insistence on good temperature control between 2 and 8°C. On the other hand, this new technology requires changes to standard operating procedures that have not been fully vetted with stakeholders and still require education and updating.

Has anyone else had experience with this? Any suggestions on how to approach these types of changes to procedures required for this new technology?

I appreciate any thoughts.

Wendy

TechNet Admin Réponse acceptée
Admin

Thanks for your comments, Pat. That is helpful to know that PATH also experienced a bit of hesitancy with Ministries and using this device. I agree with you that it would be helpful to have clarifying documents from WHO with this new technology and the shift in temperature range for this specific type of device. The Ministry of Health in Mozambique definitely looks to WHO for guidance, and apparently the PQS pre-qualification isn't enough to explain the slight shift in technology.

Zihong Réponse acceptée

Hi Serge, both Pat and Ana did a good job in explaining the ice logistics for the Arktek passive vaccine storage device in the field. I would like to add one more point.

Among the Arktek devices deployed in Senegal, Nigeria, Ethiopia, India and etc., in most cases the ice packs are frozen in a larger freezer at a district-level location, and are transported to the health posts using a portable cold box or an insulated backpack. The ice conditioning is normally performed at the health post up on receiving the ice pack. Each freezer at the district store will serve multiple Arktek devices in the district. This arrangement worked quite well and made the use of larger freezers efficient.

Ana Maria Costache Réponse acceptée

Serge Ganivet, to answer your question, since the Arktek water blocks must be arranged to lay flat when frozen, when piloting it in Mozambique, VillageReach froze them for 48 hours in large capacity freezer at the province level. The devices were sent empty, ahead of time to each individual health center location. After 48 hours, when we were ready to take the ice packs to each health center, we placed 8 frozen blocks in the WHO approved coolant box and transported them. At that point, because they were frozen, we were able to stack them and easily carry them to each site. We conditioned the ice block at each health center prior to placing them inside the device.

Pat Lennon Réponse acceptée

Hi Wendy - PATH has experience field testing Arkteks and also ran into a similar restistance to the 0 to 10C temperature range with the ministry of health. PQS specifications for all passive cold chain equipment (equipment cooled by frozen water packs) is 0 to 10C. So any system using frozen water packs in their cold boxes and carriers is already operating in the 0 to 10C range but they may not know it as cold boxes and carriers typically don't have an external temperature display. Arktek operates on a similiar principle as cold boxes and carriers but has much better insulation.

In order to gain approval to deploy Arkteks we worked with the ministry of health to explain the similarities between Arktek and other passive equipment and we shared the PQS specifications (available on the WHO PQS website) that list 0 to 10C as their acceptable operating temperature range. Unfortunately there isn't a guidance document from WHO that explains this variation in cold chain specification for passive equipment as it would help with these conversations.

Serge - To your questions. Arktek is not approved as a transport device so therefore should not be moved when loaded with ice/water packs. If the Arktek were dropped when fully loaded there is risk of damage to performance that the end user may not be able to detect. In our studies ice packs are brought from (larger) freezers to the health clinic in cold boxes once per month.

Serge Ganivet Réponse acceptée

I am also interrested to know how staff manage to freeze the Artek water pack as the size and design are not standard. The Artekcoolant packs do not fit all in small capacity freezer where we can freeze 8-12 standard water packs. Does it mean the Artek packs should be froozen in medium / large capacity freezer ? From your experience, did the staff bring the long term storage cold box to the site where the coolant packs are froozen or did they bring the frozen / conditioned packs (with vaccines probably) to the site where the LTS cold box is placed, which I think it is the easiest, but once again the design of the "Artek" packs takes much more space in the cold box for the transportation. Just to learn from your respective experiences.

Thanks - serge

Zihong Réponse acceptée

These are great questions, Wendy. The Arktek device is a passive vaccine storage device uses only ice and is capable of keeping the vaccine cold for a minimum of 35 days in a hot zone ambient environment. This device had passed rigorous testing in the lab and in the field, and was prequalified to PQS E004/041 as a long term storage cold box.

The Arktek has 8 ice blocks, which can be loaded into the Arktek device following an ice conditioning protocol provided by the manufacturer. The temperature inside the Arktek will reach an equilibrium point at approximately 0.5C for almost 4 weeks. After that the temperature will rise slowly to a maximum of 10 C. Unlike an SDD or conventional refrigerator, the Arktek is a passive device and it does not have an active cooling system. Again the temperature inside the Arktek will only rise from the equilibrium point at approximately 0.5°C. So there is no worry of freezing the vaccines!

For a refrigerator a temperature around 0.5°C is an alert! In an active refrigerator device, the temperature can fluctuate down to the freezing temperature of -0.5°C and below. In this case the risk of exposing the vaccine to freezing can be real!

The Arktek is a new technology addressing the last mile delivery of vaccines for the remote locations without proper refrigeration systems, or electricity supply. Users can reference WHO CCE Catalogue for detailed technical specification following this link:

http://apps.who.int/immunization_standards/vaccine_quality/pqs_catalogue/categorypage.aspx?id_cat=18

They can also reference clauses 4.2.2 and 4.2.6 for the official WHO specifications for long-term passive devices, where 0 to 10C is clearly specified for this type of passive cold box.

Pièces jointes
Références
  1. http://apps.who.int/immunization_standards/vaccine_quality/pqs_catalogue/LinkPDF.aspx?UniqueID=82770860-fef7-4a7e-ab0d-f702e70f8ff2&TipoDoc=DataSheet&ID=0


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