-
Publication en cours de modérationStatut publié avec succès. Il est désormais visible dans votre journal.
-
Evidence base prompts changes to global policy for vaccine refrigerators
A month ago a document titled Power Quality Challenges in LMICs - Data and Analysis was posted here on Technet Forum. Unfortunately, there has not been much feedback. I am disappointed in the lack of discussion because in my view this study presents findings which support changes in global policy for vaccine refrigerators. The paper presents data from two representative countries on the availability and quality of electric power that are major determinants of the performance of vaccine refrigerators. The data suggest that, in both countries, the variability and intermittent supply of electric power indicates that three features are needed, universally to assure continuous, correct refrigerated storage:
- Holdover passive cooling
- Integral voltage stabilizers
- Remote temperature and power monitoring
Consider these three issues as a basis for discussion.
Hold-over passive cooling
The period of ‘safe’…
Lire la suiteEvidence base prompts changes to global policy for vaccine refrigerators
A month ago a document titled Power Quality Challenges in LMICs - Data and Analysis was posted here on Technet Forum. Unfortunately, there has not been much feedback. I am disappointed in the lack of discussion because in my view this study presents findings which support changes in global policy for vaccine refrigerators. The paper presents data from two representative countries on the availability and quality of electric power that are major determinants of the performance of vaccine refrigerators. The data suggest that, in both countries, the variability and intermittent supply of electric power indicates that three features are needed, universally to assure continuous, correct refrigerated storage:
- Holdover passive cooling
- Integral voltage stabilizers
- Remote temperature and power monitoring
Consider these three issues as a basis for discussion.
Hold-over passive cooling
The period of ‘safe’ vaccine storage when power is interrupted is boosted for vaccine storage by an ‘ice-lining’ that is charged with cooling when power supply is on or when sun is shining and then provides cooling when the power is cut. The data show that interruptions of the grid supply are variable and unpredictable. So a universal policy to provide a holdover of 120 hours might replace the current standards. The holdover capacity in hours remaining could be displayed on the refrigerator to inform the user of the security of stored vaccines.
Integral voltage stabilizers
Voltage stabilizers markedly increased the percent of usable electricity supply in all refrigerators monitored during the study, both those with widely varying voltages and those with frequent variations. At present, stabilizers may be supplied as separate accessories ‘bundled’ with refrigerator purchase or they may be provided within the refrigerator product. Incorporating stabilizers universally into vaccine refrigerators could benefit repair and maintenance and would assure that sensors were correctly installed,
Remote monitoring of temperature and power
The paper describes the system of power recording that was adopted in this study. Analysis of this data has, for the first time in over 30 years, informed manufacturers, vaccine managers and international stakeholders. Power data, when used in conjunction with temperature alarm data and vaccine management should be routinely monitored by an LMIS. The collection, transmission, analysis and dissemination of information by countries should become universal.
The WHO PQS Specification Working Group might plan a discussion on the implications of this paper for the future of a universal vaccine refrigerator specification for all countries. The benefits of a universal vaccine refrigerator might be:
- A single simple standard for all vaccine refrigerators
- Rejecton of domestic refrigerators
- Hybrid use of solar and grid electricity
- Oversight of the implementation by National Regulatory Authorities
- Larger market, concentrated on a single universal standard
- Better prices
- More manufacturer interest
Publication en cours de modérationStatut publié avec succès. Il est désormais visible dans votre journal.One month ago, the LANCET (ScienceDirectRef: “Expanding safe waste management to public health systems” https://doi.org/10.1016/S0140-6736(18)32622-9), January 2019, Elsevier Ltd.) published a letter to the editor (see also attached). The letter points to the failure to sustain or expand immunization waste management infra-structure to all public health programmes. To stimulate an exchange of views the letter includes a text-box proposing four key milestones towards a single vision.
I would like to open the discussion also on Technet. The four milestones are quite general at first glance but they are based on specific experiences of the PATH/WHO Children’s Vaccine Programme that I will introduce as we discuss your own experience and areas of interest.
John Lloyd
Publication en cours de modérationStatut publié avec succès. Il est désormais visible dans votre journal.Moderator a réagi à cette publication il y a 5 ansYes, I heard the announcement too on BBC World News.
I support the motivation and interest of individual researchers and the media to anounce potential 'innovations' in a cryptic 'Breaking News' style.
In this case, as in many other releases I have read, is that the innovation is premature and vanishes as quickly as it appeared! In this case, I hope that the issues that I am about to list will be considered:
Freeze dried format is, I admit, being used in the manufacture of an increasing proportion of new vaccines. However, this format is to be avoided in the future when there is better choices because:
- Until there are vaccine delivery devices that administer powder directly in widespread use, the vaccine has to be re-constituted (mixed with diluent);
- The reconstitution of dried vaccine with diluent at the point of use is hazardous and the procedure is slow;
- Oral polio drops are enabling us to eradicate the disease without an injection and injected, killed polio liquid…
Lire la suiteYes, I heard the announcement too on BBC World News.
I support the motivation and interest of individual researchers and the media to anounce potential 'innovations' in a cryptic 'Breaking News' style.
In this case, as in many other releases I have read, is that the innovation is premature and vanishes as quickly as it appeared! In this case, I hope that the issues that I am about to list will be considered:
Freeze dried format is, I admit, being used in the manufacture of an increasing proportion of new vaccines. However, this format is to be avoided in the future when there is better choices because:
- Until there are vaccine delivery devices that administer powder directly in widespread use, the vaccine has to be re-constituted (mixed with diluent);
- The reconstitution of dried vaccine with diluent at the point of use is hazardous and the procedure is slow;
- Oral polio drops are enabling us to eradicate the disease without an injection and injected, killed polio liquid will gradually take over without an additional injection;
- Although freeze drying can achieve higher thermostability in storage than some liquid vaccines, it is very heat sensitive once reconstituted and must be used within 6 hours;
- Freeze drying is an expensive process requiring long term investment by manfacturers and some loss of flexibility.
John Lloyd
Publication en cours de modérationStatut publié avec succès. Il est désormais visible dans votre journal.Dan Brigden a réagi à cette publication il y a 5 ansSo, where are we now?
More than a year has passed since the last TechNet-21 meeting! We have a year ahead of us before the next meeting!
As time races by, I feel the need to know more about progress that is being made with the many new initiatives that were described by countries and organisations towards scaling up for maximum impact in the shortest time.
Presentations in 2017 focused on demonstrations and pilot projects designed to advance the science of cold chain technologies, monitoring and evaluation techniques. Compared to the flourish of innovations reported from most regions, the process of scale-up to national implementation and evolution of global policy seems slow. In the face of expanding demand to introduce more vaccines and to extend immunization services, we need to hear about scale-up and widespred adoption of the most robust and successful iniatives reported in the TechNet-21 sessions in Portugal last October.
Publication en cours de modérationStatut publié avec succès. Il est désormais visible dans votre journal.Aucune activité