Novel Technologies Could Make Coronavirus Vaccines More Stable for Worldwide Shipping
Ssendi Bosco has long known to fear the rainy season. As deputy health officer of Mubende District, a region in Central Uganda, she is only too aware of the threat that heavy storms can pose to her area's fragile healthcare facilities.
In early October, persistent rain overwhelmed the power generator that supplies electricity to most of the region, causing a blackout for three weeks. The result was that most of Mubende's vaccine supplies against diseases such as tuberculosis, diphtheria, and polio went to waste. "The vaccines need to be constantly refrigerated, so the generator failing means that most of them are now unusable," she says.
This week, the global fight against the coronavirus pandemic received a major boost when Pfizer and their German partner BioNTech released interim results showing that their vaccine has proved more than 90 percent effective at preventing participants in their clinical trial from getting COVID-19.
But while Pfizer has already signed deals to supply the vaccine to the U.S., U.K., Canada, Japan and the European Union, Mubende's recent plight provides an indication of the challenges that distributors will face when attempting to ship a coronavirus vaccine around the globe, particularly to low-income nations.
Experts have estimated that somewhere between 12 billion and 15 billion doses will be needed to immunize the world's population against COVID-19, a staggering scale, and one that has never been attempted before. "The logistics of distributing COVID-19 vaccines have been described as one of the biggest challenges in the history of mankind," says Göran Conradson, managing director of Swedish vaccine manufacturer Ziccum.
But even these estimates do not take into account the potential for vaccine spoilage. Every year, the World Health Organization estimates that over half of the world's vaccines end up being wasted. This happens because vaccines are fragile products. From the moment they are made, to the moment they are administered, they have to be kept within a tightly controlled temperature range. Throughout the entire supply chain – transportation to an airport, the flight to another country, unloaded, distribution via trucks to healthcare facilities, and storage – they must be refrigerated at all times. This is known as the cold chain, and one tiny slip along the way means the vaccines are ruined.
"It's a chain, and any chain is only as strong as its weakest link," says Asel Sartbaeva, a chemist working on vaccine technologies at the University of Bath in the U.K.
For COVID-19, the challenge is even greater because some of the leading vaccine candidates need to be kept at ultracold temperatures. Pfizer's vaccine, for example, must be kept at -70 degrees Celsius, the kind of freezer capabilities rarely found outsides of specialized laboratories. Transporting such a vaccine across North America and Europe will be difficult enough, but supplying it to some of the world's poorest nations in Asia, Africa and South America -- where only 10 percent of healthcare facilities have reliable electricity -- might appear virtually impossible.
But technology may be able to come to the rescue.
Making Vaccines Less Fragile
Just as the world's pharmaceutical companies have been racing against the clock to develop viable COVID-19 vaccine candidates, scientists around the globe have been hastily developing new technologies to try and make vaccines less fragile. Some approaches involve various chemicals that can be added to the vaccine to make them far more resilient to temperature fluctuations during transit, while others focus on insulated storage units that can maintain the vaccine at a certain temperature even if there is a power outage.
Some of these concepts have already been considered for several years, but before COVID-19 there was less of a commercial incentive to bring them to market. "We never felt that there is a need for an investment in this area," explains Sam Kosari, a pharmacist at the University of Canberra, who researches the vaccine cold chain. "Some technologies were developed then to assist with vaccine transport in Africa during Ebola, but since that outbreak was contained, there hasn't been any serious initiative or reward to develop this technology further."
In her laboratory at the University of Bath, Sartbaeva is using silica - the main constituent of sand – to encase the molecular components within a vaccine. Conventional vaccines typically contain protein targets from the virus, which the immune system learns to recognize. However, when they are exposed to temperature changes, these protein structures degrade, and lose their shape, making the vaccine useless. Sartbaeva compares this to how an egg changes its shape and consistency when it is boiled.
When silica is added to a vaccine, it molds to each protein, forming little protective cages around them, and thus preventing them from being affected by temperature changes. "The whole idea is that if we can create a shell around each protein, we can protect it from physically unravelling which is what causes the deactivation of the vaccine," she says.
Other scientists are exploring similar methods of making vaccines more resilient. Researchers at the Jenner Institute at the University of Oxford recently conducted a clinical trial in which they added carbohydrates to a dengue vaccine, to assess whether it became easier to transport.
Both research groups are now hoping to collaborate with the COVID-19 vaccine candidates being developed by AstraZeneca and Imperial College, assuming they become available in 2021.
"It's good we're all working on this big problem, as different methods could work better for different types of COVID-19 vaccines," says Sartbaeva. "I think it will be needed."
Next-Generation Vaccine Technology
While these different technologies could be utilized to try and protect the first wave of COVID-19 vaccines, efforts are also underway to develop completely new methods of vaccination. Much of this research is still in its earliest stages, but it could yield a second generation of COVID-19 vaccine candidates in 2022 and beyond.
"After the first round of mass vaccination, we could well observe regional outbreaks of the disease appearing from time to time in the coming years," says Kosari. "This is the time where new types of vaccines could be helpful."
One novel method being explored by Ziccum and others is dry powder vaccines. The idea is to spray dry the final vaccine into a powder form, where it is more easily preserved and does not require any special cooling while being transported or stored. People then receive the vaccine by inhaling it, rather than having it injected into their bloodstream.
Conradson explains that the concept of dry powder vaccines works on the same principle as dried food products. Because there is no water involved, the vaccine's components are far less affected by temperature changes. "It is actually the water that leads to the destruction of potency of a vaccine when it gets heated," he says. "We're looking to develop a dry powder vaccine for COVID-19 but this will be a second-generation vaccine. At the moment there are more than 200 first-generation candidates, all of which are using conventional technologies due to the timeframe pressures, which I think was the correct decision."
Dry powder COVID-19 vaccines could also be combined with microneedle patches, to allow people to self-administer the vaccine themselves in their own home. Microneedles are miniature needles – measured in millionths of a meter – which are designed to deliver medicines through the skin with minimal pain. So far, they have been used mainly in cosmetic products, but many scientists are working to use them to deliver drugs or vaccines.
At Georgia Institute of Technology in Atlanta, Mark Prausnitz is leading a couple of projects looking at incorporating COVID-19 vaccines into microneedle patches with the hope of running some early-stage clinical trials over the next couple of years. "The advantage is that they maintain the vaccine in a stable, dry state until it dissolves in the skin," he explains.
Prausnitz and others believe that once the first generation of COVID-19 vaccines become available, biotech and pharmaceutical companies will show more interest in adapting their products so they can be used in a dried form or with a microneedle patch. "There is so much pressure to get the COVID vaccine out that right now, vaccine developers are not interested in incorporating a novel delivery method," he says. "That will have to come later, once the pressure is lessened."
The Struggle of Low-Income Nations
For low-income nations, time will only tell whether technological advancements can enable them to access the first wave of licensed COVID-19 vaccines. But reports already suggest that they are in danger of becoming an afterthought in the race to procure vaccine supplies.
While initiatives such as COVAX are attempting to make sure that vaccine access is equitable, high and middle-income countries have already inked deals to secure 3.8 billion doses, with options for another 5 billion. One particularly sobering study by the Duke Global Health Innovation Center has suggested that such hoarding means many low-income nations may not receive a vaccine until 2024.
For Bosco and the residents of Mubende District in Uganda, all they can do is wait. In the meantime, there is a more pressing problem: fixing their generators. "We hope that we can receive a vaccine," she says. "But the biggest problem will be finding ways to safely store it. Right now we cannot keep any medicines or vaccines in the conditions they need, because we don't have the funds to repair our power generators."
A startup aims to make medicines in space
Story by Big Think
On June 12, a SpaceX Falcon 9 rocket deployed 72 small satellites for customers — including the world’s first space factory.
The challenge: In 2019, pharma giant Merck revealed that an experiment on the International Space Station had shown how to make its blockbuster cancer drug Keytruda more stable. That meant it could now be administered via a shot rather than through an IV infusion.
The key to the discovery was the fact that particles behave differently when freed from the force of gravity — seeing how its drug crystalized in microgravity helped Merck figure out how to tweak its manufacturing process on Earth to produce the more stable version.
Microgravity research could potentially lead to many more discoveries like this one, or even the development of brand-new drugs, but ISS astronauts only have so much time for commercial experiments.
“There are many high-performance products that are only possible to make in zero-gravity, which is a manufacturing capability that cannot be replicated in any factory on Earth.”-- Will Bruey.
The only options for accessing microgravity (or free fall) outside of orbit, meanwhile, are parabolic airplane flights and drop towers, and those are only useful for experiments that require less than a minute in microgravity — Merck’s ISS experiment took 18 days.
The idea: In 2021, California startup Varda Space Industries announced its intention to build the world’s first space factory, to manufacture not only pharmaceuticals but other products that could benefit from being made in microgravity, such as semiconductors and fiber optic cables.
This factory would consist of a commercial satellite platform attached to two Varda-made modules. One module would contain equipment capable of autonomously manufacturing a product. The other would be a reentry capsule to bring the finished goods back to Earth.
“There are many high-performance products that are only possible to make in zero-gravity, which is a manufacturing capability that cannot be replicated in any factory on Earth,” said CEO Will Bruey, who’d previously developed and flown spacecraft for SpaceX.
“We have a team stacked with aerospace talent in the prime of their careers, focused on getting working hardware to orbit as quickly as possible,” he continued.
“[Pharmaceuticals] are the most valuable chemicals per unit mass. And they also have a large market on Earth.” -- Will Bruey, CEO of Varda Space.
What’s new? At the time, Varda said it planned to launch its first space factory in 2023, and, in what feels like a first for a space startup, it has actually hit that ambitious launch schedule.
“We have ACQUISITION OF SIGNAL,” the startup tweeted soon after the Falcon 9 launch on June 12. “The world’s first space factory’s solar panels have found the sun and it’s beginning to de-tumble.”
During the satellite’s first week in space, Varda will focus on testing its systems to make sure everything works as hoped. The second week will be dedicated to heating and cooling the old HIV-AIDS drug ritonavir repeatedly to study how its particles crystalize in microgravity.
After about a month in space, Varda will attempt to bring its first space factory back to Earth, sending it through the atmosphere at hypersonic speeds and then using a parachute system to safely land at the Department of Defense’s Utah Test and Training Range.
Looking ahead: Ultimately, Varda’s space factories could end up serving dual purposes as manufacturing facilities and hypersonic testbeds — the Air Force has already awarded the startup a contract to use its next reentry capsule to test hardware for hypersonic missiles.
But as for manufacturing other types of goods, Varda plans to stick with drugs for now.
“[Pharmaceuticals] are the most valuable chemicals per unit mass,” Bruey told CNN. “And they also have a large market on Earth.”
“You’re not going to see Varda do anything other than pharmaceuticals for the next minimum of six, seven years,” added Delian Asparouhov, Varda’s co-founder and president.
Genes that protect health with Dr. Nir Barzilai
In today’s podcast episode, I talk with Nir Barzilai, a geroscientist, which means he studies the biology of aging. Barzilai directs the Institute for Aging Research at the Albert Einstein College of Medicine.
My first question for Dr. Barzilai was: why do we age? And is there anything to be done about it? His answers were encouraging. We can’t live forever, but we have some control over the process, as he argues in his book, Age Later.
Dr. Barzilai told me that centenarians differ from the rest of us because they have unique gene mutations that help them stay healthy longer. For most of us, the words “gene mutations” spell trouble - we associate these words with cancer or neurodegenerative diseases, but apparently not all mutations are bad.
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Centenarians may have essentially won the genetic lottery, but that doesn’t mean the rest of us are predestined to have a specific lifespan and health span, or the amount of time spent living productively and enjoyably. “Aging is a mother of all diseases,” Dr. Barzilai told me. And as a disease, it can be targeted by therapeutics. Dr. Barzilai’s team is already running clinical trials on such therapeutics — and the results are promising.
More about Dr. Barzilai: He is scientific director of AFAR, American Federation for Aging Research. As part of his work, Dr. Barzilai studies families of centenarians and their genetics to learn how the rest of us can learn and benefit from their super-aging. He also organizing a clinical trial to test a specific drug that may slow aging.
Show Links
Age Later: Health Span, Life Span, and the New Science of Longevity https://www.amazon.com/Age-Later-Healthiest-Sharpest-Centenarians/dp/1250230853
American Federation for Aging Research https://www.afar.org
https://www.afar.org/nir-barzilai
https://www.einsteinmed.edu/faculty/484/nir-barzilai/
Metformin as a Tool to Target Aging
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5943638/
Benefits of Metformin in Attenuating the Hallmarks of Aging https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7347426/
The Longevity Genes Project https://www.einsteinmed.edu/centers/aging/longevity-genes-project/
Lina Zeldovich has written about science, medicine and technology for Popular Science, Smithsonian, National Geographic, Scientific American, Reader’s Digest, the New York Times and other major national and international publications. A Columbia J-School alumna, she has won several awards for her stories, including the ASJA Crisis Coverage Award for Covid reporting, and has been a contributing editor at Nautilus Magazine. In 2021, Zeldovich released her first book, The Other Dark Matter, published by the University of Chicago Press, about the science and business of turning waste into wealth and health. You can find her on http://linazeldovich.com/ and @linazeldovich.