Too Cool for School – How to Fix Freezing in the Vaccine Cold Chain?

Jul 24, 2018 8:00:09 AM | Sensire



Have you ever noticed that when you start to fix something, inevitably that fix will create new problems that will need fixing? It’s the perpetual cycle of evolution and revolution that drives innovation, but also churns out new challenges to overcome. For an example of this, let me take you to the world of vaccine logistics:

1.    The Warm-Up

Initially the vaccine cold chain grew from an initiative in the 1960s and 1970s to eradicate smallpox. To fix this global pestilence, the World Health Organization staged a massive vaccination campaign that would end up eradicating the disease in the next two decades. To keep smallpox from returning, however, it was not enough to beat it down once. Continued immunity would only be ensured by vaccinating all future generations, and while they were at it, why not expand the program to cover other diseases as well?

So vaccinations fixed the problem of smallpox very nicely. But now we come to the thing I mentioned at the very start: fixing things creates new things that need fixing. Because, as you can probably imagine, providing masses of vaccines to a growing global population is not a simple undertaking. The next problem that needed fixing was how to get all these vaccines, which were highly vulnerable to heat, to the people in a viable condition.

The answer was to adopt a cold chain approach for all the vaccines zooming around the globe. This is not a minor detail in the story of how vaccines help people keep healthy, because keeping things reliably cold for long periods of time is not nearly as easy to do as it is to write. Still, with hard work and innovation it was duly accomplished. Of course there are still problems with keeping vaccines cold, particularly in the last mile, where sparsely inhabited and climate-wise challenging areas provide little in the way of power to keep electric cooling devices running. On the whole, however, we can say that keeping things cool has, at least in theory, been mastered.

2.    The Cool-Down

But here’s the kicker: we’re too good at keeping things cool. In order to keep vaccines from overheating and losing potency, we’ve adopted measures that cause approximately a third of all vaccines to be exposed to temperatures below recommendation. Which would be no trouble if the typical vaccine didn’t mind the occasional cold spell, but particularly for those vaccines that need adjuvants there is a high risk of the active part of the vaccine becoming inactive when exposed to freezing temperatures. Freeze-susceptible vaccines provide cures for, for instance: hepatitis A and B; tetanus; diphtheria, human papillomavirus, and others.

So if too hot temperatures had mostly to do with the surrounding environment and too cold more with the methods adopted to combat this, what is it we’re doing wrong? Well, there are still environmental factors at play, particularly when transporting and storing vaccines in the very north or south where winters can be harsh. For the most part, however, we’re talking of human error.

Picture this: you purchase a cucumber, stick it in your fridge and noticed a few days later how it has turned from a fresh treat into semi-liquid goop? The reason is that a fridge, while maintaining the preferred temperature on the whole, has areas where the temperature can get significantly higher or lower than what you’re expecting it to be. Storing stuff on the fridge door, for instance, makes them a lot warmer. Conversely sticking them right next to the fan will cool them right down. Cue cucumber sludge. All this holds true for vaccine storage as well. But while wasting a vegetable is a shame, wasting a vaccine can be lethal.

In addition to incorrect fridge placement, transporting vaccines in cool bags is too often accompanied by ice packs such as you might see in your domestic use. The term to notice here is ice packs. Definitely not optimal company for freeze-sensitive vaccines. The WHO, as well as many other organizations, recommend using cool-water packs instead, or conditioning the ice packs beforehand so that the vaccines cannot come into contact with the actual ice. Conditioning takes time, however, often leading to the path of least resistance, this being to chuck the ice packs into vaccine transport containers before they are conditioned.

These are the most common mistakes in vaccine cold chain, but there are others. So how do we fix too cold, now that we’re somewhat adept at dealing with too warm?

3.    Something Old, Something New

Some of the methods with which we can combat vaccine wastage are deceptively simple. We could, for instance, increase training for health workers so they would know how to maintain a continuous cold chain at the correct temperature. This should prevent the problem of unconditioned ice packs being used where they shouldn’t be. There are also other safety measures regarding the storage of vaccines in cold rooms and fridges. One such is to use water bottles to restrict access to those parts of a fridge where vaccines should not be placed. This may seem counterproductive when water bottles fill most of your refrigerator, leaving less room for the vaccines that actually require storage. Eliminating vaccine waste will in the long run still create cost savings compared to investments into more storage space.

On the other hand, we are also seeing innovative approaches for stabilizing vaccines for transportation through more scientific means. In the UK a Bath-based group has experimented with ensilication, where the biological materials, i.e. vaccines would be encapsulated in a silica cage, protecting them against denaturation and long-term storage. A NYU Abu Dhabi team proceeds with similar experiments with calcite. Coming up with a working model of the technology is slow going, however, as research into various types of coating has been going on for some time now.

It is entirely possible that this kind of research may in time eradicate the need for a dedicated vaccine cold chain, and better training will also help with vaccine waste. For the moment, however, there is one more method which seems to work extremely well in eliminating temperature excursions in the vaccine cold chain. I am talking, of course, about real-time temperature monitoring.

4.    Follow the Money

First some numbers: according to Markets and Markets the global vaccine market was worth 34.3 billion USD in 2017. In 2015, 59 percent of vaccines procured by UNICEF Supply Division were freeze sensitive. When we factor in that a third of all vaccines get exposed to too low temperatures, more than a sixth of UNICEF vaccines are in danger of degradation due to freezing.  With UNICEF vaccine procurement totaling 1.6 billion USD, that is 270 million USD worth of lifesaving product that is at stake in UNICEF immunization operation alone.

Compared to the global vaccines market worth, the possible wastage sum from freezing alone rises to almost 6 billion USD annually. Of course the 6 billion USD is the absolute worst case scenario when thinking about waste, but there is data supporting the view that this is not that far out. Consider, for example, that 25% of vaccines reach their destination degraded because of improper logistics. That would be 8,5 billion USD worth of vaccines bought that won’t do what they should. But let’s say only a tenth of the alerts is actual freezing. That’s still 600 million USD worth of vaccine waste. So how will real-time data help you save some of that money?

5.    Real-Time Revolution

Adopting real-time monitoring has a proven effect on cold chain success, in one case decreasing freeze alarms by 40 % and waste by 12 %. Globally, that would be 2.4 billion USD worth of vaccine that don’t need to be examined for alerts. Even if we take the view that only 10 % of freeze-sensitive vaccines actually were wasted, that’s 72 million USD annually that could be saved just by decreased freeze damage. Other examples of real-time benefits abound.

Now consider the fact that on the whole those vaccines that are not freeze-sensitive are heat-sensitive, and you can see how the amount of work going into just monitoring temperatures and verifying vaccine viability would be staggering. Digital real-time data can help not just by providing alerts on temperature exceptions, it can lighten the workload for health workers considerably by making comprehensive vaccine cold chain monitoring a whole lot easier.

But real-time is not just about getting alerts when temperature reaches freezing. The thing about automated continuous monitoring is that there is verified long-term data available. That means that while recognizing a momentary temperature spike can help deal with the immediate reality of possible spoilage, it is the trend that provides real opportunities. It creates significant benefits for analytics and process development by way of recognizing and correcting problem hotspots.

Further down the line you could add to this the kind of kinetic modeling which would allow you to accurately predict logistics performance before the vaccines have even been shipped. With access to the real temperature profiles of vaccines during shipping, kinetic modeling could also be used to ascertain the actual degradation undergone by the vaccines due to temperature fluctuation.

Now the only thing left to do is to actually adopt real-time monitoring to vaccine shipments and storage. You don’t have to go it alone, however. If you’re serious about saving both money and lives, Sensire can help. Get in touch; together we can make the world a healthier place.

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For more information on this and other related subjects, why not check out our most comprehensive resource yet: Temperature Monitoring in the Pharmaceutical Cold Chain

Themes: Temperature Monitoring, Cold Chain Monitoring, Reducing waste, Vaccine Cold Chain


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