The Special Fridges Behind The COVID-19 Vaccine, Why It’s Surprisingly Difficult To Be That Cool

One of the big stories last week was the announcement of results from clinical trials that suggest a new COVID-19 vaccine developed through the joint effort of the American and German companies Pfizer and BioNTech is strongly effective in providing immunity from the virus. In the midst of what is for many countries the second spike of the global pandemic this news has been received with elation as well as becoming the subject of much political manoeuvring.

While we currently have two vaccine candidates with very positive testing results, one of the most interesting things for us is the need to keep doses of the Pfizer/BioNTech vaccine extremely cold until they are administered. Let’s dig into details of the refrigeration problem at hand.

Special Fridges for -80 °C (-112 °F)

This rather unappetising view is the scar on my arm from my smallpox vaccination.
This rather unappetising view is the scar on my arm from my smallpox vaccination. You probably don’t have one of these if you’re young, because vaccinations like this one across whole populations successfully eradicated smallpox worldwide by 1980.

This particular vaccine must be refrigerated at -80 Celsius until it is ready for use. This presents a significant problem for any mass vaccination programme, because while -80 degree freezers are a done deal in terms of manufacture they are not commonly to be found in community healthcare. Labs and major hospitals may have them, but we’re told that even in a developed country the general practitioners who will be tasked with administering the vaccine have until now had little need for one. If this presents a problem in a place with significant resources then it is magnified significantly in less wealthy regions of the world, because to effectively fight a global pandemic it is imperative that the whole planet be vaccinated to avoid a remaining reservoir of infection.

I’m not biologist, but every school biology class teaches the for-the-children basics of vaccination. In the late 18th century Dr. Edward Jenner successfully inoculated a boy with the cowpox virus to bestow immunity to smallpox, and from that developed the science of immunology. It’s likely we will all have received similar vaccines which our high-school biology simplifies for us as weakened or less-potent relations of the target, and the fact that past killers are now receding into folk memory is testament to their success.

These are the jabs my doctors and their team in Oxfordshire administer by the thousand, and they can protect generations of British kids with them using only a relatively conventional refrigerator. What’s so special then about the Pfizer/BioNTech vaccine? The answer lies in its method of operation, instead of exposing us to a pathogen it’s a so-called RNA vaccine. It contains a fragment of the virus’ genetic material, which once administered enters our cells and triggers their immune responses to the coronavirus. The problem we are told lies in the fragility of the RNA, and to prevent it degrading an extra-cold fridge is needed.

The Logistics Of Last-Mile Cryogenic Transport

The inner workings of a two stage refrigerator. David M. Berchowitz and Yongrak Kwon, CC BY-SA 3.0.

As engineers our obvious next question then is what makes a -80 °C freezer so special? We’re on firmer ground when it comes to the operation of a fridge: it’s a heat pump with a radiator, expansion valve, and condenser, through which a propellant is pumped by a compressor. The condensing propellant causes the cooling of the inside of the refrigerator, and the resulting captured energy is radiated as heat to the room by the radiator. There’s a limit to the level of temperature differential that can be created by such a heat pump, so the -80 degree freezers have two of them in series. They’re less efficient and more expensive to produce than your domestic fridge, but their manufacture is well established. We’re told it’s simply that there aren’t enough of them where they would be needed, and thus it’s interesting to think for a minute about the implications of that.

Jurassic Park style improvisation is probably inappropriate.
Jurassic Park style improvisation is probably inappropriate. J.accurate, CC BY-SA 3.0.

One might think that equipping all doctors with suitable -80 degree freezers would be the obvious course, after all while they aren’t cheap in domestic terms (a quick Google search suggests $10,000 and upwards), to governments throwing billions at the pandemic their cost would be easily manageable. But the problem there lies in the supply chain, the global market for them in non-pandemic times is not enough for there to be manufacturing capacity to meet unexpected huge demand. It’s unlikely that domestic refrigerator plants could be tooled up to make them in bulk within a reasonable timescale, so the prospect of a brand new -80 degree freezer landing in my doctor’s surgery seems slim. One might expect that such devices could be requisitioned for the effort from their existing owners, from universities and research labs, but therein lies another problem. These vaccines are for injection into patients, and therefore they must be protected from contamination at all costs. The idea of a fridge fresh from a university chemistry lab where Ph.D students have been using it to store highly toxic organometalic compounds is simply not tenable if serious risk to patients is to be avoided.

Another option might be to eschew refrigeration, and instead opt for different cooling methods such as passive cooling with liquid nitrogen. The manufacturing capacity exists to make this substance in industrial quantities, and it is already something that sees extensive use in medical environments. The snag is that it is used at the consumer end of medicine for cryongenic treatments such as wart removal rather than for cryogenically cooled transport or storage, so there would be a need for an entirely new infrastructure to put in place. Cryogenic sample transport boxes are a done deal, but aside from any supply issues with a sudden demand for tens of thousands of them they can only guarantee the low temperature while their payload of liquid nitrogen has not evaporated. They alone are not a replacement for an infrastructure of -80 degree freezers, though they might provide a substitute for active refrigeration in lengthening the last stage of delivery.

A bright spot in this story is that a second vaccine developed by Moderna doesn’t require the extreme refrigeration, and can be stored at 2-8°C (35-46 °F) for up to a month. This would make reaching parts of the world without infrastructure for extreme cooling possible. But in the near-term we will certainly need both of these vaccines and as many doses of them as can be produced and delivered as possible, since two doses are needed for each person in world population that numbers almost 8 billion.

As we will no doubt see from the various solutions our governments will pursue over the coming months, there is no magic bullet for the unexpected mass deployment of a cryogenic vaccine. For the UK I’d expect to see distribution centres at major hospitals which have the required freezers, with the day’s doses being delivered each morning to vaccination sites. We are however a relatively small and densely packed country for whom the challenges are different to one spread over a huge area, and a world away from those in some developing countries. With this operation assuming a global significance it’s unexpected to think that the key to the end of the pandemic does not only lie in the hands of the scientists creating the vaccines, but also with the refrigeration engineers responsible for its safe arrival at the point of use.

Editor’s Correction: The article originally indicated that Pfizer and BioNTech were both German companies. Pfizer is an American company and GioNTech is a German company.

162 thoughts on “The Special Fridges Behind The COVID-19 Vaccine, Why It’s Surprisingly Difficult To Be That Cool

  1. “One might think that equipping all doctors with suitable -80 degree freezers would be the obvious course, after all while they aren’t cheap in domestic terms (a quick Google search suggests $10,000 and upwards),”

    Am I missing something? A quick Google search for me (literally, -86 C freezer) shows plenty of single-compressor compact -86 C freezers well under $10K, more in the $5-6K range. The big ones are obviously way more than that.

    1. My guess what is missing from their statement is the caveats of “freezers that have redundant protection, and are certified to operate in a medical facility to much higher standards than commercial devices”. There’s a reason that medical and military equipment cost much more than seemingly equivalent commercial offerings. Commercial standards are much more lax, usually barely above basic safety.

      I wouldn’t trust thousands or possibly hundreds of thousands of dollars of vaccines to a cheaper single compressor fridge with a few percent tolerance temp accuracy and no fault detection/alarm system. Sure those features can possibly be bodged onto a commercial fridge but then hospitals would have to qualify the system meets minimum reliability requirements themselves.

      1. Yeah, you’re right. Crazy for me to believe that a device whose list of primary uses includes “hospital rooms” and “medical clinics” would somehow be appropriate for medical clinics.

        It’s easy to get fooled, y’know? I mean, especially when the manufacturer specifically lists it as being under heavy demand due to the desire for cold storing COVID-19 vaccines, and when they list them as CDC and VFC compliant. Those tricky guys.

        “cheaper single compressor fridge”

        I’m not sure why you’d expect a single-compressor system that can reach these temperatures to be *cheaper*. They’re more reliable than a cascade design since there’s only 1 compressor that can fail.

        1. Oh crazy me for assuming I know anything about the medical device industry despite working as an engineer in the medical device industry as we speak. But of course you know so much since you did a quick google search.

          Also you never specified which fridges you were looking at so how is it my fault for not knowing the ones you were referring to were validated for medical use? You cant blame me for your ambiguity, if you want to talk about specific devices, then how about specifying which ones?

          Also having a single failure point is indeed NOT more reliable than a redundant design (keep in mind you brought up cascade and I never mentioned cascade). In the off chance that you are not aware, redundancy and cascade are two different things.

          1. I don’t doubt you know plenty about the medical device industry. But I find it *really* odd that you think there’s this huge supply of cheap crappy -80+C fridges out there.

            This is where I think the disconnect is coming from: I’ve *looked* for cheapo freezers/thermal chambers that go down to -80C out there, because I don’t need wacko bells and whistles on them for lab use considering I’m not using them with things that spoil. Instead, I end up having to buy one that has multiply-redundant power inputs, external backup cooling, audible/visible alarms, WiFi connectivity, and medical certifications. Because those are the only ones *out* there.

            I mean, if you can point me to crap -80C freezers that cost way less than the medical ones, please do.

            “Also you never specified which fridges you were looking at so how is it my fault for not knowing the ones you were referring to were validated for medical use?”

            Because I literally told you what I searched for? Literally “-86 C freezer,” and then oh hey look, there’s that benchtop K2 one for ~$5K. To be fair, maybe that search isn’t repeatable because of creepy Google tracking. But in any case, again – these aren’t like, outliers.

            I mean, Thermo-Fisher’s freezers are all like, $10K-ish at list price online, so maybe that’s where the article was looking at? But their stuff’s always like ~2x more expensive than everyone else’s.

            “you brought up cascade and I never mentioned cascade).”

            Uh, the reason I mentioned single-stage is (points to article) – “there’s a limit to the level of temperature differential that can be created by such a heat pump, so the -80 degree freezers have two of them in series.” Maybe you missed that? I was trying to ask why the author thought that single-stage compressor freezers weren’t viable at these temperatures, and why they cost $10K.

          2. $5K vs $10K, when governments are doing mass projects even with the scale the difference won’t matter much, they’ll be spending much more on the staffing and delivery vehicles… The trouble won’t be so much cost, as to whether there is enough manufacturing capability, especially with the damage that locking down rather than going with old-fashioned hygiene based pandemic mititgation methods might well have done to the economy, betetr hope that the factories which make super-chill fridges haven’t gone bust already.

          3. “$5K vs $10K, when governments are doing mass projects even with the scale the difference won’t matter much”

            To be clear I totally agree on this – it’s not like “$10K, OMG that’s bad” and “$5K, OK great!”

            My original comment was really just wondering where the article got its information from, since it seemed strangely specific – implying single-stage wouldn’t work, starting at $10K, etc. – when the same simple Google search that the article implied showed that information was fairly off.

          4. The cascade was already mentioned in the article: The described system where one circuit cools the low temperature sircuit is called a cascade.
            Redundancy was never an issue in the article.

        2. I think, a design which reaches -86°C (or -100) can not be true single stage. Although it uses just one compressor. If you are interested, you can google autocascade refrigeration. More development effort and possible cheaper production.
          There are also cryotherapy chambers, where patients are exposed to -100C for 1 or 2 minues to cure or ease some illnesses. I think this is quite successful for some autoimmune diseases.
          I have been told, that they use expander cycle turbine systems similar to the liquefaction of air.
          Our temperature test chambers here (down to -70°C) are classic 2 compressor cascades. But they are not really cheap, I think around 10k€ is also their price tag. But compare that to a day or a week in a test lab.

          1. “Our temperature test chambers here (down to -70°C) are classic 2 compressor cascades. But they are not really cheap, I think around 10k€ is also their price tag”

            Yeah, I agree the single-compressor guys are probably autocascade (I shouldn’t’ve said ‘single-stage’ above, that was a typo). I know when we were looking at them they were lower power + claimed higher reliability, but they were also more expensive at the time. Most likely by now the obvious production cost savings (compressors are expensive) probably has trickled in.

            The smaller (-80) chamber we have was around $5k – the larger one’s like $15k, but it’s huge (cubic-meter scale), and plus those are both thermal test chambers rather than just freezers. Kindof amazed me there was virtually no price difference between a low-temp freezer and a low-temp thermal chamber.

      2. A refrigerator is not a medical device. It’s not even diagnostic equipment. There’s nothing special about a medical sample fridge or freezer.

        If you actually worked in the medical device industry, you’d know this.

      3. That’s quite easy: In both sectors, medical and military, other people’s money is spent. Money, that the governments do not have to earn themselves. So other prices are possible, than when you have to sell e.g. a household fridge, to somebody, who has to earn the money before he can spend it.
        Medically certified stuff is always expensive.
        And a “single compressor fridge” is nothing bad. It’s propbably something called an “autocascade”. Contrary to the already explained casceded low- and high temperature system with separate compressors, you can use a single compressor for both different refrigerants with careful system design and some gas/liquid separators.

        1. There’s no such thing as “medically certified” freezers. The primary users for -80’s are researchers storing samples; very few things in a hospital are stored at -80. Even in research, -80 use is minimized as much as possible because the things are massive energy hogs, generate a huge heat load in whatever room they’re in, they frost up like crazy (and defrosting them is a royal pain as you can imagine), and they break, a LOT. They are shockingly unreliable. Our building had an extensive monitoring system just for the freezers for when they failed – they come with dry contacts for failure alarming.

          It is increasingly common for LN2 “refrigeration” systems to be used because they tolerate power failure, don’t generate heat load, and they’re extremely simple and reliable compared to the freezers.

          I speak as someone who actually worked at a medical research school AND a hospital. Whole bunch of nerds here talking about things they know nothing about.

          1. True freezers are not “medically certified” but the monitoring system are/should be NIST certified yearly. I can only speak to my experience in healthcare but I have seen -80C freezers used for several things including but not limited to bone and specimen storage. Agreed defrosting is a major pain but thankfully most of the units I have encountered work for years with only minimal maintenance.

          2. Thanks for clarifying: that’s actually what I was trying to say (“medically certified” should’ve been in quotes there). I searched very, very hard for -80C freezer/thermal chambers without crazy bells and whistles intended for safety/tracking purposes, and they aren’t there. They’re pretty much all geared to the medical field.

            Plus, of course, all the bells and whistles are a ridiculously minor cost on top of the *actual* cost to build the thing, so it’s not really surprising. Really I just was hoping for a less-robust option, but “light-duty freezers/chambers” aren’t exactly a thing.

            “they frost up like crazy (and defrosting them is a royal pain as you can imagine),”

            Yeah, that’s one of the reasons we opted for a chamber with an GN2 purge cycle input instead of a freezer, as it significantly slows the frosting/condensation process. Granted that’s obviously not practical with a freezer used for access as opposed to long-term testing.

            Colleagues of ours have had problems with freezers as well – thankfully the one freezer we briefly used (before switching to a thermal chamber) was very new/high-end (we were able to have it for a few months for free to test it for them) so it didn’t really have any problems.

          3. The HC facility I work at just installed a -80degC freezer in theatres for bone storage and this is only at a 100 bed regional hospital. Monitoring is done purely by someone manually reading the display each day and if it drops (raises) they ring the supplier. No fancy monitoring.

            I understand though that the bone and body part storage has a wide tolerance.

    2. I’m not sure why you are holding this strawman argument with yourself under multiple names but it doesn’t matter what might happen to currently be available for sale. As the article says, there has never been a market for so many freezers that go that cold. Manufacturers don’t invest in building extra production lines to sit unused just in case they might one day get an order 1000s of times larger than their typical yearly sales. They would quickly buy up the supply and it might be 2022 before enough more can be produced.

    3. I did not read through all the replies and sorry if this was already addressed. A -80C freezer for $6K will be subpar quality and much to small. From first hand experience your looking at $18K for a lab quality freezer to store Pfizer’s vaccines in bulk. As of writing the minimum amount Pfizer will ship is 5K doses or 2.5K vials. On top of that physician offices will most likely not give the vaccine, it will be large health networks and chain pharmacy. With that said, it is 2020 so who knows.

      1. “A -80C freezer for $6K will be subpar quality and much to small.”

        I believe the “small” part, although given that all of those freezers have essentially *disappeared* in the past few months due to demand, I’m going to guess that the value of smaller freezers isn’t nearly as low as you’re saying. I mean, it’s easy enough to imagine a chain ordering a large bulk quantity and then distributing them to pharmacy chains. The ones I’ve seen will easily store hundreds, which isn’t useless.

        The “subpar quality” I can’t comment on, although I’ve worked with several of those manufacturers’ freezers and they’re all fine. Pretty much everyone’s always been the same ballpark pricing for me, except for Thermo Fisher, who’s always been like, double.

    4. It is quite possible to make reliable -86C freezers with a single stage… we had a nice one in our lab a few years ago, that we ran at -80C without difficulty. However, those single-stage freezers require running on a specific refrigerant gas that is hard / expensive to obtain.
      When it eventually broke down and needed a compressor replacement (after running with a broken cooling fan for who-knows-how-long) it turned out that it seemed the importer had lied as the gas inside was not one permitted for import into my country. The only alternative was refilling with a gas that cost several thousand ($16k) per bottle. Instead, we refilled it with a different gas and now it only runs at -45C unfortunately.

      1. I dunno. I got a shipment of epoxy one time from Henkel and I just gave them my shipping account info (protip: don’t do this). I was out of town when the thing arrived and it sat on my porch for 3 days in a styrofoam cooler with dry ice in a bag. When I opened the cooler, there was still dry ice in there.

        I think the shipping charges came to $238 for my “free” sample – overnight delivery + hazardous material (dry ice).

        1. Why not? At a festival a group had two boxes of dry ice (about 30*40*20 cm) and when they left after about 4 days in one was still 1/3 left – and a nearly full, frozen bottle of tequila which of course rescued for the next festival. And no, it was not cold there, we had daytime temepratures up to 36°C.
          Another group made the mistake and forgot to close their box during the first night -> warm beer for the rest of the time.

      2. For less than $100 I can get a substantial amount of styrofoam sheets from Home Depot. Cut them up and glue them together to get a container big enough to hold the vaccines and a couple of 1 foot cubes of dry ice. Schedule deliveries of dry ice from a local supplier, 1 cube ought to be good for about a week.

    1. Pfizer plans on using the spoke and hub model. Dry ice will be used to ship the vaccines to distribution hubs like health networks same day or next day. From there the hub will break down the ‘payload’, Pfizer’s term for a 5K dose container, and store the contents in freezers. When it is go time a tray of 194 vials will be loaded into a specially designed container with 50lbs of dry ice and sent to the vaccine site.

    1. R1150 if you look at Wikipedia’s “list of refrigerants” is Ethene (Ethylene).

      And that could in theory be made in small quantities by the dehydration of ethanol with sulfuric acid. You would need to make the reaction happen at a low temperature well below the boiling point of ethanol 78.2 °C (172.8 °F; 351.4 K). Then you would just need to capture the Ethylene gas which boils at −103.7 °C (−154.7 °F; 169.5 K), filter it to neutralise any remaining acid vapour and compress it to 5,040 kPa ( ~730 PSI ; ~50 atmospheres). The last part is the difficult bit.

        1. Using Apples, Apricots, Bananas, or Pears which naturally produce Ethene is interesting, but I’d hate to see the energy input versus yield to isolate it at any useful quantity.

          As some fundamental level I would guess that it might be a similar type of reaction to the above but probably involving natural acids in the fruits and hydrogen sulfide as the fruit literally starts to rot. It may be fully organic but you would have to deal with a concoction of other organic compounds, possibly carbon dioxide, methanethiol, dimethyl sulfide, methane, hydrogen sulfide, ammonia, methanol and maybe hydrogen and lots of others. So you would definitely need to separate them as much as possible and distil off the Ethene, which sounds like a lot more work. And you would still need to compress it to get it to a liquid. My suggestion is inefficient, but using Bananas would be worse, at least in my mind.

    2. The real question is why would you want it?

      I’m still not sold on flammable refrigerants, when these propane fridges start burning people’s homes down I guess we’ll relearn that lesson too.

    3. I don’t know, but I think it was the same stuff, a friend used for his -100°C project – a cascade for CPU overclocking. Perhaps he had to get it from Poland. But it is not a fluorinated gas considered as an environmental hazard. It is flammable, but that is ordinary propane also.

    1. We haven’t had DNA maps for a hundred years. Times have changed. It’s only been the last 10-15 (if I remember correctly) years that DNA sequencing has become something you can do in a week. Via Wikipedia:

      “The first DNA sequences were obtained in the early 1970s by academic researchers using laborious methods based on two-dimensional chromatography. Following the development of fluorescence-based sequencing methods with a DNA sequencer,[6] DNA sequencing has become easier and orders of magnitude faster.[7]”

      These days it can be done in 3 days.

      I understand being skeptical with all the corruption and everything, but anytime someone says something is impossible I feel like they’re really just speaking for themselves.

      1. Now you can even buy RNA or DNA samples made to order from commercial labs. There are youtubers, who present there projects on genetiic editing, making GMOs like yeast which produces spider silk in the brew. I think to remeber even people who did their own gene therpy agaist an inherited disease or deficiency.
        If you have this kind of ressorces plus the knowledge of “hundred years” of work about corony virus, then I have no problem in understanding that it is possible to develop such vaccines in a worldwide effort

    2. The virus was isolated, cultured, sequenced and imaged within a week or of a case landing in Australia.

      Once you have the genomic sequence, getting equipment to crank out mRNA sequences is not difficult.

      The main holdups are the phase I, II and III trials to assess safety and efficacy, followed by the issues of logistics wrt distribution.

      mRNA vaccines are a new and exciting development. I wonder if Harrison was accused of corruption and treated with the same disbelief with his first chronometers, when vying for the prize for determining longitude accurately.

    3. Looks like you’re really, really dumb. Coronavirus family is huge and diverse. We’re just lucky that SARS, MERS and SARS CoV2 have an exposed vulnerability that make a vaccine possible. Most other coronavirus strains are much harder to address. You know no crap about immunity and vaccine development, and yet you dare to have an opinion. It’s utterly disgusting.

      1. Anybody is allowed to have an opinion and even to talk about it. Like anybody is allowed to be dumb :-)
        I am glad, that we have chances to get rid of this measures and the stupid masks in a -hopefully – near future.

    4. Anyone else sad that legitimate discourse seems to have been permanently interrupted by these ends-justify-the-means/sports-team-style political hacks? The timing is highly suspect obviously. Don’t hate on it just because the truth hurts your sports team.

  2. Please be more careful do not make statements with finality especially with highly contagious diseases.
    Small Pox is not eradicated and has some degree of activity still within the world. Also as noted by the op, because so few are vaccinated now against it, it is an ideal bio-terrorism weapon. Read Active cases exist throughout the world. It’s just not a big cause of death anymore, but it’s still out there.
    As for liquid nitrogen and vaccine stores, having used a dewar ( for cryogenic storage, I would suggest those. I might point out these are relatively cheap by comparison ( and definitely reusable and are relatively common. The loss of liquid nitrogen is very slow if one chooses a large enough capacity, it seemed to only need topped off every 3 months with normal use. They aren’t toys and are dangerous if one doesn’t secure them properly etc.
    This might seem “specialized” but, it’s not and heck FARMS have used them for a long time. The big issue is refilling the liquid nitrogen or using one in a remote location.
    Other than those two things I appreciate the effort put into the article.
    The 2nd vaccine will be a “we’ll see” still at least it possible to work. The newer more infectious variants of the COVID-19 may be more controllable with the vaccine. The question now is “how much” and who “gets it”.
    Controlling temperatures at the 2-8C range is easier, I wonder if they tested lower temperatures to extend storage time, surely they have data over a wide range of temperatures, likely the “target” storage time is 30 days (or 28 just long enough to administer the second round) hence why they have that temperature citation available. I always have to remember, “these people aren’t here to help people they are here to deliver a product that may help people”.

    1. From
      The last naturally occurring case of smallpox was reported in 1977. In 1980, the World Health Organization declared that smallpox had been eradicated. Currently, there is no evidence of naturally occurring smallpox transmission anywhere in the world.

      The only known cases of lab-exposure smallpox were in 1978. There hasn’t been a single reported case of smallpox in 40 years.

    1. It is indeed smallpox. When we adopted my sister from Asia she was required to get vaccinated for a whole host of things one of which was small pox and so she has the dimple just like my parents but I do not.

    2. People still get polio shots today so if they left scars like that young people would still have them. So only old people have smallpox vaccination scars, and while the young may laugh when the terrorists release the smallpox next year who will be laughing then.

      1. That scar, from american vaccination in the 70’s, is polio administered by high pressure injection, like would happen if one was not careful with a airless paint sprayer. That method doesn’t require needles, thus more efficient and less syringes needed to get millions of children vaccinated. I remember mine, we all lined up in the cafeteria at school and one by one we got our polio vaccine sprayed into our upper arm.

        1. It’s a Brit scar not a US one, and it’s my smallpox scar. I remember going to the doctor in Bicester for it with my mother. They used the same arrangement for smallpox vaccinations.

          I was pretty much the last generation of Brits to get it.

          1. My mother has a scar like that from when she immigrated from England to Australia. As they had to pass, by boat, though some countries that had Smallpox, they were all immunised. In Australia, the Polio vaccine was given as drops on a sugar cube.

    3. To be fair my smallpox shot doesn’t look like that. It looks like a little red raised spot on my upper arm. I got myne in the military, what a terrible time to get it, spent three weeks very carefully not touching it while having to keep it bandaged and dry. Not easy while you’re neck deep in mobilization training with only one opportunity a day to perform any kind of hygiene.

      Speaking of not touching it, I knew a guy who managed to screw that up and accidentally cross contaminated his gentlemen’s parts. Not only did he have to treat that area the same way as his shoulder but it also came with the same three week hands off period. He was only 6 days away from being done with the shoulder when it happened!

    4. When I was a child, the polio vacciantion was administered orally: “Two drops (on a sugar cube) and you are protected” was the slogan to tell the people how easy you can prevent a severe disease. Unfortunately this vaccine is not available anymore and you have to get an injection also against polio.
      I also have the smallpox-scar on my arm.

  3. It’s interesting engineering challenge – create small, cheap and effective cryogenic device. Simpliest thing that comes to mind is Peltier cryocoolers. Yes, they are not very efficient, but cheap, simple and reliable. In any case, any cryosystem needs power, so, why not Peltier?

    But one thing still make me fascinated – why nobody questioned the reasons why this vaccine needs -80? Usually cryogenic temperatures used in biology to keep something _alive_. No known vaccines need that conditions for storage. Viruses and their parts used in vaccines are not alive, they are just complex chemical substances, not something alive. So, why they really need -80?

    1. I’m not a biologist/virolgist/anything like that but if I had to guess I’d say something in the vaccine denatures/breaks down enough to affect effectiveness at temps above -80. No idea specifically what, but it’d be interesting to take a look at the research publications that are undoubtedly being written about it.

      1. > I’d say something in the vaccine denatures/breaks down enough to affect effectiveness at temps above -80

        So, how it supposed to work in humans under +36.6? If it denaturates above -80, under +36.6 it will denaturate immidiately just in process of injection.

        Meanwhile, another option to get -80 for cheap is liquid nitrogen. It is dirt cheap and produced in enormous quantities as a byproduct of air separation. It’s really a waste on the air separation plant, because main products are CO2, oxygen and argon. All you need to make a -80 storage is a Dewar with the price much less than $10k or even just a plastic foam box.

        1. The process of degradation could take time so it may be fine once brought up to room temp, injected within a relatively short period and a person’s immune system starts reacting to it, but storage for more than a few hours at higher temps may not be acceptable.

        2. It’s really a waste on the air separation plant, because main products are CO2, oxygen and argon.

          Mostly right, but liquid nitrogen is not a waste product of an air separation plant, it’s the primary product, along with oxygen. Argon is often a primary product. CO2 is a waste product. In any case most air separation plants can produce many tons of liquid nitrogen per hour.

          1. nah, the nitrogen really is kind of a waste product, the industry mostly wants everything else that’s being distilled but the nitrogen – oxygen, argon and the other noble gasses. (look at the insane price of xenon…)
            The only thing that actually *needs* craploads of nitrogen is ammonia production, if the air distiller is not next to a chemical plant, they will not have a primary use for the nitrogen and will selling it dirt cheap.

          2. According to Wikipedia, a modern ammonia plant does not need separated N2, They use water, air and methane (natural gas). Under the baseline, the Oxygen from the air is used to burn the carbon from the Methane.

    2. In a lot of cases, vaccines use DEAD viruses so that the body can encounter them without risking an actual infection. And if that is the case here then the cryogenics are probably to keep the viruses from breaking down before the recipients immune system has a chance to identify them.

      1. Viruses can’t be DEAD. They are not alive. They could be working or not. Usually something that just looks like working virus is enough for immune system to learn how to fight working one. But to learn, there must be something to interact for some period of time. If it breaks down at above -80, how it supposed to work in human body with +36.6? There will be nothing to study for immune system in seconds.

        1. It’s not a dead virus. It’s just mRNA which codes for the spike protein on the virus. You screw around with the nucleoside so that the immune system doesn’t recognize it, but the cells can translate it perfectly fine. Then you wrap it in a little lipid ball. This is why mRNA vaccines have the potential to be so ludicrously useful – you’re essentially just writing code to use a human body as a chemical factory. Multiple vaccines can be exactly the same except for the mRNA coding. You’re telling the cells “dude, make this protein so your immune system freaks out and makes the antibodies to attack it.” There’s super-low risk because the only part of the virus you’re making is just the spike protein.

          “If it breaks down at above -80, how it supposed to work in human body with +36.6?”

          Because it only needs to survive in the body for a short time, whereas it’ll take a much longer time in storage. mRNA is stupidly fragile, so you just slow the chemical clock to a stop to ensure that enough of it will survive. I mean, Moderna and Pfizer both use mRNA, but they’ve got stupidly different temp requirements. So does it have some sort of phase transition at -80? No, of course not.

          So why does Pfizer’s need such a lower temperature? Well, I mean… look at Moderna’s *name*.

          1. If so, do we really need to solve complex problem with cryogenic and spend a lot of money (tax or insurance – in any case, it will eventually end on ordinary people), just to allow one private company to make some profit from their unfinished result? Shouldn’t Pfizer provide that refrigerators for free, along with their very sensitive product?

            I have nothing against interesting engineering challenges, but in that case this looks at least strange.

          2. There are plenty of labs that already have ultracold storage or are willing to expand their storage capabilities. Send the Pfizer ones there. Note that ultracold stuff may become more common, so it’s a reasonable investment for certain places – why ask Pfizer to buy them, if clinics are willing and it ends up saving them money in the long term?

            This isn’t about profit at this point, it’s about rapid distribution and delivery. If you’ve got an easily solvable problem that *doesn’t* involve making more work for the company *making* the vaccine, do it.

            I’d understand your argument if Pfizer was the only one out there, though, but given that there are two options, this is an obvious “divide and conquer” solution.

          3. So, why this article, if there is no problem in cryostorages for Pfizer vaccine?

            Even if there is no problems with storage devices, there will be human factor. Cryostorage need more attention, than ordinary fridge. So, if vaccine needs very special storage conditions and become useless if they are broke, than final efficency could drop down to unacceptable values. So, this could end with rapid distribution and delivery of nothing.

            There may be very specific conditions for very specific and unique things. But when it goes to mass market, especially in urgent situations there souldn’t be something very specific. It’s like, say bread delivery in case of disaster, when just one of suppliers says, that you have to transport their product only on platinum pallets, otherwise it will rot.

          4. “So, why this article, if there is no problem in cryostorages for Pfizer vaccine?”

            Got me. I didn’t write it! I mean, if Moderna’s vaccine has to be pulled because of some toxicity things, it’d be an issue in my opinion.

            Again, Pfizer’s storage conditions are more strict, sure. But there are plenty of places that *can* handle it, and pretty much anyone can handle the Moderna guys. So this is just a logistics issue of routing the appropriate vaccine to the right place.

            It seems silly to complain about the Pfizer vaccine’s storage conditions when the current alternative is “none.” It would’ve been nicer if they had easier conditions (like Moderna) but that might’ve cost them like, 6 more months. Whereas right *now* the Pfizer vaccine helps rollout speed to places that can handle ultracold storage.

          5. So, the real question is not “how to make cheap -80 fridge”, this could be resolved by logistic, since, as far as I understand, in any case Pfizer wouldn’t be able to make enough vaccines to think about worldwide coverage.

            The real question is the technical reason Pfizer vaccine needs -80 and how to fix it.

            It’s like if somebody will try to create a complex system to collect all leaked oil from car engine and put it back, instead of fixing a leak.

            Also it is very interesting how private companies still play competition and trade secret games even in situation when all of them will definitely sell out their product, and could do it only once.

          6. “The real question is the technical reason Pfizer vaccine needs -80”

            I’ve mentioned this multiple times. Low temperatures slow mRNA degradation. Pfizer likely hasn’t done enough testing to know how the formulation they have (the modified nucleoside+lipid encapsulation) behaves at higher temperatures. It’s almost certainly just a testing issue.

            It’s a time issue. Pfizer’s getting the vaccine to market ASAP. They don’t have nearly the experience of Moderna. But they can still produce -and have produced- buckets of them. That’s still valuable.

            *Any* amount of vaccine you can get out there now is useful.

          7. @Stanson: Why should they provide something for free? In the end somebody has to build the device – he wants money for it.
            “Provide for free” could only mean, the cost for the refrigerators are calculated into the product prize. Like with Coca-Cola or Red-Bull fridges. Or with a “free” mobile phone together with your two year service contract. Normally this is not cheaper in the end for you This is only interesting for people who “need to have” the newest smartphone, but can not afford it at the beginning (or sometimes not really at all). But it’s only a form of down payment, more expensive overall.

        2. Pfizer vaccine is using a lipid shell vector to deliver mRNA into your cells. Then your cells will produce viral proteins that immune system need to be trained for. So, the problem here is getting mRNA inside your cells. One simple way is to just have a raw lipid shell that’d merge indiscriminately with your cell membranes. It does not need to last long to do so. Many simpler viruses do the same. A more robust way is to use a viral vector – i.e., a shell of an actual virus with its advanced ability to infiltrate host cells, like the Oxford vaccine is doing. Adenovirus have a full protein capsid, and therefore quite stable in normal conditions. The downside is that you’d develop an immunity to this capsid proteins too.

        1. Well, i was a bit extreme. Whatever I was reading this AM was saying that if poured out on to a surface, it would be not effective in a short time. The need for the deep freeze is for transport and storage til use. Once at the point of use, it would be thawed and kept in some less cold storage for a few days. The problem is that RNA is a very fragile structure and susceptible to degredation by enzymes and such. The extreme cold slows that process down during transport and storage til within a few days of use.

        2. I’ve read all of your comments, you are unhelpfully pedantic, and seem to be hinting at conspiracy (“fascinated – why nobody questioned the reasons why this vaccine needs -80?”). Please, leave the science to the scientists and don’t spread misinformation.

          1. > you are unhelpfully pedantic

            Everybody have to be extremely pedantic, if it is about their health.

            > and seem to be hinting at conspiracy

            OK. Conspiracy of what? You think that there is some conspiracy? Tell us more, please.

            > Please, leave the science to the scientists

            I’m a scientist. So, you leave science for me. That’s OK.

            > and don’t spread misinformation.

            What kind of misinformation? What do you mean? Who spread it? Please be more specific.

            Now, speaking scientifically:

            Article says, that there are two similar mRNA vaccines. One needs -80 storage, other do not. So, scientifically speaking, extremely low temperatures is definitely not required for the storage of mRNA vaccines, and -80 storage is only Pfizer’s drawback. Pfizer is a private company making profit selling vaccine. Why should anybody have to solve Pfizer’s drawbacks and pay for it? That money could be spent for more vaccines from other companies, who did their job better.

          2. Great, this response shows that you may not have read even the cursory info on the web that I have. The difference in the required temp has to do with the lipid shell and whatever other stuff they have mixed in to try to make it harder.

          3. Stanson, again, you’re failing to understand what was being said (in both the article and my comment).

            I’m impressed that you think you’re more qualified than the people working on the vaccines (both the science side, logistics side, and every other side), what type of scientist are you?

          4. BigTechDude, you did not answer my questions.
            Please, describe what kind of conspiracy you find in my posts. I’m very curious now.
            Also, I’m waiting exact description of misinformation you find.

            If you answer to my questions, I’ll answer to yours.

            Spritle, so this is just a technical problem in Pfizer recipe. I’d like to find more about component, that require -80 for storage and possible replacements others use. Did you find any real details on the web? I can’t. Only something like “Because the specific formulations are secret, Liu says, it’s not clear exactly why these two mRNA vaccines have different temperature requirements.” and similar opinions.

          5. Why should anyone pay for the -80 fridges? They don’t. Don’t, if you don’t want it. The price of their vaccine will drop if they can’t shift it.

            Though Many governments have I think pre-ordered the unknown vaccine to ensure they got first dibs on it. So they’ve already paid.

    3. I was wondering the same thing, and I did some research a couple of years ago, where I concluded that Peltiers are actually quite horrible when either the temperature difference is very high or the energy being moved is high; they seem great until you actually try to use them.

      When the temperature difference increases, the thermal leakage inside the Peltier element also increases, and at some point, it isn’t even able to compensate for it’s own internal leakage, much less actually move any energy from the cold side to the warm side. For a reasonable good Peltier element, the maximum temperature difference you can achieve, with 0 energy being moved, is about 75C.

      However, considering the vaccines would already be cooled when they are placed inside this device, you would only need to compensate for the leakage through the package, not actively cool the contents any further. If you would keep the Peltier cooled device inside a regular freezer at -20C, the difference of 60C might be within the range of a Peltier device.

      It is possible to stack Peltier devices, but this doesn’t help a whole lot, since the outer device has to transport all the heat dissipated by the inner device, on top of the energy being moved by the inner device. This severely limits the attainable temperature difference across this outer device, but on the other hand, even a small temperature across this outer devices increases the headroom for the inner one.

      I’d think -80C would be attainable with either a single or stacked Peltier devices inside a regular freezer. These devices don’t need to be very expensive, and if you have several units, with temperature sensors inside them to provide an early alert in case of a failure, you could simple move the vaccines to another one and provide the redundancy that way.

      1. Stirling cryocoolers are really quite impressive. They do have moving parts, but some varieties have zero sliding contact between any of the moving parts so they have an extremely long lifespan.

    4. DNA is stable, because it’s double-stranded and they stabilize each other.
      RNA isn’t really stable. One base dimerizes or spontaneously isomerizes. (It’s uracil, and is probably why DNA doesn’t use it.) The long floppy unstabilized molecule can twist around and self-interact, even self-catalyze. (Tom Cech got a Nobel for discovering this.)
      The Arrhenius reaction gives a good approximation for the lifetime of molecules as a function of temperature. Unsurprisingly, it’s exponential, decreasing with increasing temperature.

      The vaccine only needs to last long enough to get into your body and stick to some B-cells for long enough for them to start proliferating and producing antibodies. That may only be a few hours. However, it also needs to last from production through quality testing, distribution, storage, and distribution to individuals, which may be weeks, or months in rural or economically struggling areas.

    5. The speed of most chemical reactions is temperature dependent, often doubling with every 10 degrees Celsius. Keep the vaccine for months at -80C, a day or so at -20C, a few hours at 0C, tens of minutes in the body to generate the immune reaction.

      Also, realize that it doesn’t go bad instantaneously when the time is up, it’s just that as time passes a greater portion of the molecules become broken.

      1. I look into few scientific papers (just googled “immune response speed”) and it seems that immune response is not that fast, you need at least hours and some decent concentration of pathogen to kick it. So, tens of minutes are far from reliable margin.

        If you take into account that it is mRNA vaccine, it does not directly initiate immune response, but instead make your body to produce substance to start it. In that case you also need some significant time to get the level of substance high enough to kickstart immune response, so mRNA should not degrade long enough and be in decent amount.

        What if Pfizer just could not produce enough active substance to allow higher storage temperatures and just try to make ordered amount of doses using less ingredients and use that -80 storage to compensate natural storage loss?

    6. Proteins and mRNA chunks do not need -80. It’s a lipid shell that requires such a storage – it’s a literal soap bubble, and as such it’s very unstable. Coronavirus itself is also enclosed in a lipid shell with few protein inserts, and it also does not last long for this very reason.

      1. Similar ModeRNA vaccine don’t need -80. So, you definitely don’t need -80 for mRNA vaccine storage. It is simple logic. So, what is real difference beetwen two vaccines? What exact component in Pfizer vaccine needs -80? Is it an active component (mRNA itself, poorly choosen lipid around it, etc.) or just some emulgator or, I don’t know, pH buffer or something else?

    7. Such an inefficient device needs much power – which is not easy in logistics. For -80°C you need to stack at least 3 or four peltiers. No, that is no way to go. As it is already discussed – and I think even mentioned by the manufacturer of the vaccine – transport cooling will be done with dry ice. Easy, relativey cheap and it needs no power.
      Yes, complex chemical substances which must not react or deteriorate before use.

  4. For cascade refrigeration a “mixed refrigerant system” would probably work out cheaper to make (You can use a single compressor to simultaneously compress both work fluids) and therefore it would be faster to manufacture. And with less moving parts there is less to go wrong.

    The main disadvantage with using mixed refrigerants is that its lower limit is the freezing point of the mixture, but at -80 °C (-112 °F) that would not be a problem.

  5. The ModeRNA vaccine is also an RNA vaccine– hence the name. I wonder if they have some special sauce that slows down RNA degradation. Perhaps they can license the technology to Pfizer/Biontech. While commercially adventageous, it would be bordering on sociopathic to withhold such information during a fricken pandemic.

    1. Given Moderna’s history, I’d say they just did their homework as to knowing the time/temperature curve on the formulation they have *first* – they’ve been doing it longer. Whereas Pfizer probably said “screw it let’s get efficacy,” and tell the supply chain to handle it. They’ll probably relax the storage requirements later. It takes time to figure out what combinations of temperature/time still retain efficacy.

      “it would be bordering on sociopathic to withhold such information during a fricken pandemic.”

      Assuming that both Moderna and Pfizer’s vaccines are both safe and effective, it makes way more sense to just have Moderna/Pfizer both focus on mass production, direct the Pfizer vaccines through the chains that can handle it and the Moderna ones through the ones that can’t. Retooling Pfizer’s vaccine would require it to go through clinical trials again.

      1. For labs doing RNA extraction for sequencing there are a couple of commercial solutions for preserving RNA in tissues at fridge to room temperature. The best known are probably RNAlater/RNAProtect, which claim stability at fridge temperature for up to a month, so there are ways to preserve RNA. There are a few home-made recipes floating around and the emphasis seems to be metal chelation and protein precipitation. I can only guess that Moderna figured out a way to do this which is patient-friendly and doesn’t inhibit the effectiveness of the vaccine.

      2. In some ways, because it specifically makes a single and deliberate change to cells using the RNA strand, this type of vaccine could have less side effects and be safer than earlier vaccines (although such earlier vaccines are still very safe and side-effects quite rare) which cause more complex immune responses. Still, we’d be in a much better position for rolling out this vaccine now, and getting it as widely welcomed as it ought to be, if we’d spent the last >6 months handling covid like the previous way pandemics have been dealt with (see the flu pandemics of the 50s and 60s, or how ebola was handled when it broke out in west africa in 2014/15/16, or zika in central america) with rigourous hygiene but otherwise normal life (accepting the inevitability of some spread, and thanking our luck that for most except the elderly covid is usually quite mild) rather than decimating our liberties and economy in a vain attempt to do the impossible (stop a virus pre-vaccine). Now we’ve got a vaccine, which is great, but we need to learn the lesson that putting society on hold when waiting for one is more harmful than the virus. Vaccines beat viruses, until you have got a vaccine rolled out everywhere you just have to live normally but hygienically, the way Tegnell recommends. Actually open windows and hand washing would be well worth keeping in normal times anyway.

        1. I would not call it “change to cells”. The mRNA is not integrated into the genome. It is also not self replicating. Perhaps you could compare it to a heavily attenuted virus, although in that case the proteins are the major reason for the immune response. But there are viral vector based vaccines where the virus is able to replicate to some extent. So it’s RNA gets also into the cell and is active.

  6. minor technical nit: “The condensing propellant causes the cooling of the inside of the refrigerator”; actually, it is the /evaporating/ refrigerant that causes cooling — the condensing refrigerant causes the heat to be dumped out. It seems counter-intuitive until you realize that it is the process of mechanically forcing evaporation/condensation that makes it a heat pump working against the expected flow of thermal energy across the gradient.

    1. I would not even call that minor. It’s getting the operating principle completely the wrong way around..
      Came here to point out just the same. Evaporation “costs” heat, that’s also how those cooling sprays work that are used for sports injuries. Condensation releases the heat from the fluid again.

  7. I heard a great analogy yesterday that puts into perspective why it’s so hard to maintain the cold chain…

    Imagine that it was your job to deliver a pint of ice cream to everybody in the country.

    But… it’s not 2020. It’s 1920, and even in the cities there are only a handful of large commercial freezers.

  8. So in a world where it took MONTHS to make enough face masks and face shields available to keep hospitals running, now we’re talking about the need for refrigerators on a massive scale?

    1. It’ll be like ventilators, they tried mass producing them but then realised they weren’t actually much help for covid patients, a specific cocktail of drugs given early was much more effective. If they mass produce, or plan to, ultra-cold fridge tech then we ca be sure they’ll soon decide they prefer a vaccine which can be stored at higher temperatures. Lets hope they can find a vaccine candidate that can be done through microneedle patches, those can be kept at room temperature, are trivial to administer, people can do it themselves, and can be sent through normal mail infrastructure (could fit in a letter envelope), think how quick and efficient a mass vaccine rollout could be with microneddle patches instead of needing hypodermics used by trained personnel at specilaist centres.

  9. Why not keep them centralized and then ship to the administration site in a cryogenic dewar with something like liquid nitrogen. Only has to hold until administered. Presumably we are not looking at long term storage.

  10. The cooling tech is more interesting that the vaccine tech, which is not needed. Why they thought that going down that route was a good (and equitable) idea is baffling. Meanwhile in Queensland Australia researchers have come up with a brillion biotech hack that holds the antigen in the correct shape so as to ensure that effective antibodies are produced by the body.

  11. Wouldn’t we be best off waiting to see if some of the other vaccine candaiates, the Oxford one, the Astrazeneca one… can be perhaps stored at room temperature and used for microneedle patches, get rid of those dreadful hypodermic and provide a much less painful (and less needing of specialist nurses trained in doing injections) route for administaration. Some of the patch vaccine concepts, tested for the likes of measles and flu vaccines, are stable enough to send through normal mail, think how helpful to a mass vaccine campaign the ability to use normal non-refrigerated delivery chains, and not need nillions of needle trained nurses, could be! We need to start getting such patch vaccines manufactured. We need to end the cruel and destructive lockdowns immediately, going back to proportionate, precedented non-dictatorial pandemic management techniques, Donald A Henderson, mastermind of smallpox’s eradication stated in a 2006 biosecurity paper on repsiratory pandemic management the importance for communities’ overall health of preserving normality whatever a virus throws at you. Then as soon as the vaccine patches can be ready, because patches are easily packed in envalopes, and so easy to administer that people could do it themselves upon getting a vaccine patch in a letter, surely that is the way to go for mas vaccination campaigns?

    1. There’s also reports about a “breath from the bag” powder vaccine technology, trialled in india at one point, given that covid is a respiratory infection one wonders if this too could be an alternative to hypodermics. Not sure of whether the breath-bag is quite as easily storable and shippable as the patches though.

  12. Remember that the idea is to get as many people vaccinated as possible, as soon as possible so I think dry ice or nitrogen are perfectly acceptable methods for short term storage. You can fedex something on dry ice anywhere you want and get it couple days at least.

    Since governments are presumably paying for the vaccine (definitely in the US where billions of tax payer dollars were invested), they should be able to determine if there is some special tricks to keep the vaccine stable and demand sharing technology in this case. Often defense contracts require exactly these kind of disclosures and give the government limited licensing rights to these technologies.

      1. You make that sound like it’s a bad thing. Aren’t governments supposed to stimulate and fund things that private companies can’t/won’t do?
        If NASA hadn’t been created, would SpaceX be around now?

  13. Interesting reading the comments section here with all the folks who are smarter than the experts. Wonder if they’re the same folks who are smarter than NASA’s scientists & engineers every time something goes wrong in space?

  14. Why do we need both vaccines again? Just because having two means twice as much available? If that’s all then I think that under threat of a possible eminent domain seizure Moderna should license theirs to Pfizer and whoever else is capable of producing it. Then they can just produce that much more of Moderna’s vaccine. And don’t feel sorry for them, I didn’t say they had to license it for free. Everyone involved will make a lot of money.

    But if for some reason we must use the vaccine that requires the extra cold freezers then forget about equipping every doctor’s office and pharmacy. Install what fridges we can get on busses and start driving circuits until everyone is covered.

    1. We have three promising vaccines in the pipeline. Pfizer/Moderna are both mRNA based and J&J is a more traditional vaccine. I foresee us getting more then one brand’s vaccine to get better immunity, IE Pfizer/Moderna then a year later J&J. If you want to go down the rabbit hole look into mRNA vaccines, could help prevent cancer in the future.

    2. “Why do we need both vaccines again? Just because having two means twice as much available?”


      “I think that under threat of a possible eminent domain seizure Moderna should license theirs to Pfizer and whoever else is capable of producing it.”

      You *really* think that would help? The other companies would still have to figure out how to produce it, retool equipment, Moderna would be forced to oversee production, etc. And for what point? To deal with a problem that we can solve with logistics?

      Pfizer already has production capability for their vaccine *right now*. Asking them to screw around to make it easier is insane – *weeks* literally makes a difference here. The EUA got submitted today. It makes no sense to say “well, thank you for your vaccine, but it’s too hard to distribute.” It’s logistics, and they’ve known about it for a long time. You could *not* have forced Pfizer to shift over to Moderna’s production earlier because we *didn’t know* if Moderna’s vaccine would work.

  15. People tend to forget, that Vaccines are often for healthy people. To help protect the sick, and continued spread of infections/disease. For those of us with Auto Immune diseases, Taking immuno suppressants and other medical issues that make us susceptible to complications. The first rounds of vaccines are often not an option. Not matter what most “health care Professional’s ” will tell you. It takes much longer to develop vaccines that are tested properly and won’t case problems for this demographic.

  16. Although you could use some refrigerants like butane or propane as propellants, they are usually called refrigerant, if they are used to produce cold and not heat and motion in an engine.

  17. Dry ice reaches nearly -80°C and you do not need much more then a styrofoam box and the dry ice. It’s cheap enough that people use it on festivals to cool (and sometimes accidentially deepfreeze) their beer cans.
    So I think that could be a comparatively easy solution t this problem.
    Of course, if some buerocrats get their hands in and require something like “medically certified dry ice” then things become artificially difficult.

  18. I doubt a single stage refrigerator could cool to -80C using a legal refrigerant. I know from experience running an an environmental stress-screening chanber, that a single stage compressor with R134 refrigerant and condenser cooled with 15C ground water had no problem pulling down linearly at 5 degrees C per minute until -20C, below which it exponentially tapered off to -40C and could not go lower.

    1. That’s not a question of legality – you can not break nature’s laws anyway :-) Also the (now) illegal refrigerants would not allow single stage from -80°C to room temp.
      Also it is a question of the definition of “single stage”. Is an air liquefaction machine “single stage”? At least it uses only one refrigerant (air, although it is a blend of e few gases). Or a CO2 compressor to make dry ice? But of course, these machines do not use the conventional vapor compression cycle.

  19. There are many Dry Ice production facilities throughout the US, so it makes sense to transport and store the vaccine in a styrofoam container with a block of dry ice – You just have to boldly label to TRANSPORT AND STORE IN A WELL VENTILATED AREA!. A block of sublimating dry ice will displace all of the air in a closed office with lethal carbon dioxide. Most airlines will not let you carry more than two kilograms of Dry Ice on the airplane.

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