TechNet-21 - Forum

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  1. Omesh K. Bharti
  2. Supply chain and logistics
  3. Sunday, 21 February 2010
http://www.timesche nnai.com/ index.php? mod=article&cat=General&article=47839 Now vaccines can be stored at room temperature 02.18.2010 (GMT+5.5) London: For the first time scientists at Oxford University have found a way of keeping vaccines stable without refrigeration, even at tropical temperatures.The technology has the potential to revolutionise vaccination efforts, particularly in the developing world where infectious diseases kill millions of people every year, by removing the need for fridges, freezers and associated health infrastructure.The work published in the journal Science Translational Medicine involved collaboration between the university scientists and a company, Nova Bio-Pharma Technologies.Scientists carried out the proof-of-concept study, showing that vaccines they are developing could be stabilised for months using Nova's patented technology, called the Hypodermic Rehydration Injection System (HydRIS)."Currently vaccines need to be stored in a fridge or freezer," explains lead author Dr Matt Cottingham of the Jenner Institute at the University of Oxford."That means you need a clinic with a nurse, a fridge and an electricity supply, and refrigeration lorries for distribution" .He added: "If you could ship vaccines at normal temperatures, you would greatly reduce cost and hugely improve access to vaccines. You could even picture someone with a backpack taking vaccine doses on a bike into remote villages.”The team demonstrated it was possible to store two different virus-based vaccines on sugar-stabilized membranes for 46 months at 45 degree Celsius without any degradation.The vaccines could be kept for a year and more at 37 degree Celcius with only tiny losses in the amount of viral vaccine re-obtained from the membrane."We've shown that a very simple way of heat-stabilizing vaccines works for two viruses that are being used as the basis for novel vaccines in development, " says principal investigator Professor Adrian Hill of Oxford University."This is so exciting scientifically because these viruses are fragile. If we are able to stabilize these, other vaccines are likely to be easier," he said.The method involves mixing the vaccine with the sugars trehalose and sucrose. The mixture is then left to slowly dry out on a simple filter or membrane.As it dries and the water evaporates the vaccine mixture turns into a syrup and then fully solidifies on the membrane. The thin sugary film that forms on the membrane preserves the active part of the vaccine in a kind of suspended animation, protected from degradation even at high temperature.Flushing the membrane with water rehydrates the vaccine from the membrane in an instant."The beauty of this approach is that a simple plastic cartridge, containing the membrane with vaccine dried on, can be placed on the end of a syringe," explains Dr Cottingham.Pushing a liquid solution from the syringe over the membrane would then release the vaccine and inject it into the patient.Professor Hill adds: "The World Health Organization’s immunization programme vaccinates nearly 80 per cent of the children born today against six killer diseases: polio, diphtheria, tuberculosis, whooping cough, measles and tetanus."One of the biggest costs is maintaining what's called the cold chain making sure vaccines are refrigerated all the way from the manufacturer to the child, whether they are in the Western world or the remotest village in Africa," he said.If most or all of the vaccines could be stabilized at high temperatures, it would not only remove cost, more children would be vaccinated, he said. Dr. Omesh Kumar BhartiM.B.B.S.,D.H. M.,M.A.E. (Epidemiology)Directorate of Health Safety and Regulation, Himachal Pradesh
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Omesh K. Bharti Accepted Answer
Dear Sir, Thanks for the detailed reply. I agree many vaccines are heat stable but it is not mentioned on the vials. As the major buyer of these vaccines is WHO/ UNICEF, they can put up a condition on the suppliers to write on the vials " Can be kept upto 30 degree for 30 days and not to be restored" or any other approproate wording so that the health worker could take them to remote areas. Many health workers face termination for not keeping the vaccines at 2-8 degree even if the electricity is a problem.secondly I donot agree that a new mechanism needs to be developed for sugar-glassification technology, one can always reconstitute the powder vaccine, as is done in many other cases and give it to the child. Regarding cost and legal issues, they can be sorted out if one has the will to do that. Thanks, Dr. Omesh Kumar BhartiM.B.B.S.,D.H.M.,M.A.E.(Epidemiology) Directorate of Health Safety and Regulation,Himachal Pradesh+91-9418120302 [[email protected]][email protected][/email]; [email][email protected][/email] --- On Tue, 23/2/10, zaffranm wrote:
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  1. more than a month ago
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Michel Zaffran Accepted Answer
Thank you to Dr. Omesh Kumar Bharti for posting this article. The news it reports has received a lot of media attention over the past few days, and in many media around the world. While I personally believe that any progress towards more stable vaccines is great news and takes us in a very good direction I would like to make a few comments that may give some perspective to the "discovery" announced by the Oxford University 1) The first efforts to stabilize vaccines in sugar started in the late 1980's early 1990's. Financial constraints and then legal fights around sugar-glassification technology IP issues have prevented these discoveries from having any substantial impact so far . 2) Extensive work done on the issue of vaccine stabilization has been done by PATH (http://www.path.org) . Since 2003, PATH has worked under funding from the Bill & Melinda Gates Foundation on a project to assess the technical and commercial feasibility of stabilizing vaccines for developing country immunization programs. Many of their recent publications can be found on our web-site at: http://www.path.org/projects/vaccine-stabilization-news.php.- The head of this effort at PATH is ms Debra Kristensen [[email protected]][email protected][/email] 3) Many vaccines are already quite heat stable It is also important to note that many vaccines today on the market are already quite heat stable for extended period of time. The attached table shows that some vaccines can actually withstand a fair amount of heat exposure. However the range of vaccines that are commonly delivered by the Expanded Programme on Immunization (EPI) have very different heat stability profiles: the Oral Polio vaccine (OPV) being the most heat sensitive and Hepatitis B (HepB) and Tetanus Toxoid (TT) being the most heat stable (but also the most sensitive to freezing!!!) One current route being explored in order to assist developing countries with the logistics constraints they face with their immunization programme and the cold chain , is to encourage manufacturers and regulators to reflect the true heat stability of the vaccines they license in the prescribing information of these products. This would allow, in many cases, the products to be used for a limited period of time (e.g. up to 30 days) in a higher temperature environment ( e.g. 30°C) . At the moment, unfortunately all products are simply licensed for use between 2 and 8 ° C no matter what their true stability is 4) Do we still need a cold chain? The cold chain, with its simple and rather strict rules can be perceived as a burden for countries, however, beyond the need to have refrigerators in place through the country, the establishment of the "cold chain" has been a very powerful process to create what has actually become the "backbone" of immunization programmes, made of simple managerial rules as well as strong logistics and supply systems. The Cold Chain has made it possible for EPI to reach out to over 80% of the children under one year of age all over the world and achieve coverage rates higher than with any other public heath intervention. While processes and formulation approaches do exist and new ones are being developed to improve the heat stability of vaccines, industry is in fact reluctant to apply these processes to existing, already licensed vaccines. Indeed , the cost associated with the re-licensing of an existing product are such that they do not see the advantage (from a financial or market perspective) of going this route. At the moment the public sector provides no incentive for industry to improve existing products. If such incentives could be put in place (e.g. the public sector could signal that they would accept to pay a higher price or guarantee a certain level of demand for more heat stable vaccines)) then perhaps we could see a change in the products being developed and licensed. Even for new vaccines, the goal of industry is understandably to license and bring the product to the market as quickly as possible to start generating revenues. Additional efforts required to improve the heat stability of the product or even to carry out tests to document the true heat stability represent delays which cost money and for which no market incentive or compensation mechanism currently exist. 5) Can the Oxford University help transform immunization programmes ? A new technology, like this one, can help trigger some changes and possibly contribute to more discussions around a possible new immunization paradigm; However this technology is not perfect, the sugar-classification methods of stabilization result in dried products that must be reconstituted with a diluent before they are administered. So , if the need for refrigeration is removed, the technology introduces an additional constraint, the reconstitution step. There might be a way to design single-dose devices that perform the reconstitution in a self-contained manner which would improve ease-of-use and safety, but these are likely to be costly. Furthermore, one technology alone will not be sufficient to transform immunization programmes. A range of new technologies will be required as well as a combination of other very critical factors which would constitute an environment that is conducive to the widespread adoption of the new products: incentive structures put in place by the public sector to encourage a range of companies to move in this direction as there will need to avoid monopolistic situations which would not be good for the price of the products , the confirmation of the interest/ demand of recipient countries that will be using these products and the associated financing mechanism regulatory pathways need to reflect the true heat stability of vaccines in the prescribing information as long as some vaccines continue to require active refrigeration either permanently (oral polio vaccine for instance) or at least at the time they are reconstituted (Measles, Yellow Fever, BCG for instance) some cold form chain will continue to be needed Michel Zaffran Senior Adviser WHO/IVB & Director, Project Optimize _______________________________________________ Optimize - Immunization Systems & Technologies for Tomorrow A WHO-PATH Collaboration Department of Immunization, Vaccines and Biologicals World Health Organization | 20 Avenue Appia | CH-1211 Geneva 27 Switzerland | http://www.who.int/immunization * [[email protected]][email protected][/email] | (office +41.22.791.5409 | (mobile +41.79.210.4501| ##text##
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