By Benjamin Brits
JSE-listed company Renergen recently introduced the Cryo-Vacc. A vaccine storage technology that is driven by the natural properties of helium. Cold Link Africa had the opportunity to discuss the design and concept with chief executive officer, Stefano Marani.
Renergen is the country’s first, and only current on-shore petroleum production right-holder, essentially placing them centre in the oil and gas space. The company has roughly 187 000 hectares of production right in the Free State, South Africa.
Interestingly, our gas in the Free State has the world’s highest concentration of helium. Helium is actually an incredibly rare gas and is thus highly valuable. It has primarily been used for industrial purposes.
Aside from filling party balloons that most people are familiar with (which is only about 5% of the market), helium is used in the medical industry for MRIs, used in the manufacturer of cell phones, TVs, microchips, computers and many more applications. Basically, none of the modern-day technology would exist without helium being used in the process, and there’s no substitute for helium either.
“The major property that lies behind helium as a cryogen, is that it’s the coldest substance known to man. In its liquid form it holds at minus 269 degrees Celsius, and it never solidifies, which is another important characteristic. Comparatively, nitrogen is solid at that point. Helium has commonly been used for deep-cryogenic applications and it reveals other interesting properties when you start getting to ultra-low temperatures. This makes it significantly better for cooling, when compared to elements like dry-ice or nitrogen,” says Marani.
The opportunity for Cryo-Vacc was fast tracked by the Covid pandemic, although vaccine storage goes far beyond the current global condition and is required for many other vaccines that rely on long periods of cooling. The synergy in creating a vaccine storage device was by utilising the existing business model of Renergen, which already takes gas out of the ground.
Transportation and distribution of bulk vaccines also formed the main consideration in creating this product. In cryogenics, liquids are used. Typically, nitrogen is used for ground-based transport and helium for air-based transport. The reason for this variance is that helium is very expensive, while nitrogen is relatively cheap. For ground-based transport, nitrogen is better suited because there is less concern around the payload that you carry in terms of the mass, and nitrogen is heavy.
Helium, by contrast, is extremely light and when you’re putting something onto an aeroplane, you are generally paying per kilogram. The cost differential, in terms of the additional kilos that you’re paying on nitrogen, or carbon dioxide (dry ice) versus helium, dwarfs the extra cost of the helium.
“Other than weight, there is a cost advantage to choosing helium because you further achieve 12 times more cooling power from helium per kilogram, than you do from nitrogen or carbon dioxide – this is another significant value,” Marani continues. “The next advantage that you gain is from a safety perspective. You’re limited to a very small quantity of carbon dioxide or nitrogen that you may put onto a plane because both elements are dangerous in confined spaces. As they boil off, and because they sink, you’re likely to asphyxiate people. Helium has the opposite property in that when it vaporises, it rises and allows a lot more time to be able to react to any leakages.”
Comparatively, while you are able carry between 40 000 to 60 000 vaccines in a plane using nitrogen or carbon dioxide (because of the safety element and their cooling power), with helium, you could carry over half a million vaccines which means that you are saving on transport costs on very large payloads of vaccines.
Currently, the longest hold time that you get with dry ice, or cold plates is around three days. The other drawback with these solutions is because you have a such a short span of time and limited delivery mechanism for the cooling, you have no ability to vary or control the temperature.
How the system works
Marani adds, “With a liquid such as nitrogen or helium, we vaporise the cryogen and put it through a series of valves, pipes and heat exchangers achieving the exact temperature that is required. The particular temperature is then subjected to the cased vaccines and the excess expelled. This means that you have actual and accurate temperature control to within a very narrow band. With this critical temperature control, we can avoid seeing the significant number of vaccines being wasted. The World Health Organisation estimates that over 40% of vaccines globally, not just Covid, but all vaccines are being wasted, because of this factor.”
The Cryo-Vacc has a 20-to-25-day hold-time without any need for electricity, and conditions include the same hold time in hotter areas (even stored in the sun). This is achieved by the unique engineering.
The cryogen, in its vaporised state, can easily determine at what point you need to introduce the gas to the vaccine chamber. This process is also important in order to avoid or develop freezer burn because the vaccines are too cold, and you don’t warm them up because the gas is too hot. The storage case is then also insulated with literal ‘space-age’ materials, far along from what is considered normal insulation materials for the refrigeration industry.
“Our technology enables us to speed up or slow down the boil rate of the cryogen by building up pressure in the unit. We use that pressurised gas at a very low temperature and send it through a maze of pipes. Valves direct the gas, depending on its temperature, to where it needs to go. At the right temperature it passes within a fluid through the appropriate pipe that is in close proximity to where the vaccines are stored, keeping them at the exact temperature point. Temperature probes are also installed in the unit, and if the temperature gets too warm, then an impulse is sent to the chamber translating to “boil more cryogen” where a tiny charge executes followed by the gas passing through the set of pipes, valves and heat exchangers again, delivering the cooling power to the vaccine chamber,” Marani describes.
The vaccine cases are each custom ‘coded’ or set up’ according to the client’s determined temperature point to hold their vaccines, that can be set as low as minus 150 degrees Celsius. The vaccine cases function on a pay-per-use basis. This customisation also allows facilities to have multiple units at different temperatures as their own needs determine.
The Cryo-Vacc is thus set to deliver the required temperature parameter for a predetermined period. The gas will boil off over that period and on expiry, the unit will revert to ambient temperature, essentially shutting itself down, and can be either replenished for another pre-determined period or stored for use at a later stage for years.
Storage sizing
Sizing was a particular element to decide on as the parting shot getting the concept out the gate was to start with a very small case. However, although the initial response to that option was not ideal “because the case was perceived to be too small”, the biggest factor to negotiate was understanding the delivery of vaccines, while some potential clients wanted a solution to hold 10 000 vials.
“Transportation and distribution of bulk vaccines also Transportation and distribution of bulk vaccines also formed the main consideration in creating this product.”
The detail involved in this comes around because every vial holds six doses. And every dose takes 15 minutes to administer. If you consider having just 1 000 vials, you have 6 000 doses. That is 90 000 minutes of administering time. 90 000 minutes of giving injections, assuming an eight-hour day, translates to over 187 days to handle those 1 000 vials. Building the Cryo-Vacc for these parameters would mean you need a 187-day hold-time in order to get through the vials, which proves impractical.
“We made storage more manageable by doing various realistic and practical evaluations and came to the result on a large case holding 780 vials, which needs six nurses to inject in 25 days – which is manageable for bigger facilities. We then designed another case holding 100 vials for 25 days for smaller facilities. We have also had requests for high volume storage and when comparing our technology to traditional electric options, the overall costs of our technology produced a result of a fraction of the cost of buying the traditional freezers – showing that this technology overall is significantly cheaper than the current methods available,” Marani notes.
Obviously simple
“The reason that Cryo-Vacc works, is because it was such a glaringly obvious solution that it was initially viewed as quite a silly idea. But those are generally the ideas that make the most sense. The way that we looked at this challenge was by focusing on the fact that when you boil a gas, there’s still a lot of energy left in the gas that shouldn’t be discarded, like everyone does. The gas-form holds the temperature range that you need, and you can control the temperature range in the gas-form more easily than you can in a liquid-form. The approach that then led to the world’s first helium vaccine storage case is simple – use the gas, not the liquid. It gives you the temperature control needed where other systems fail,” Marani says.
Moving forward there is already great interest in the product both locally and importantly from international parties. Manufacture is set to start in South Africa and then be expanded further as production increases. This is more than just a Covid vaccine solution – polio, smallpox, TB, and even the flu jab needs minus 20 degrees Celsius storage. There are none, nor will there be any ambient temperature vaccines on this planet. Precise temperature control and monitoring of vaccines will always be an integral part of the custody cold chain.
Renergen plans to further review their technology scope based on this new product and test the viability of use in other elements of the cold chain, including refrigerated transport.
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