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Sweden has so far signed agreements with four vaccine manufacturers. Two of them, Pfizer and Curevac, make so-called mrna vaccines that require extreme cold to be stored for a long time. It is about minus 70 degrees, cooler than the average temperature on Mars.
Pfizer’s vaccine is not approved yet, but the company is already developing a lyophilized variant. The company states in an email to DN that it would facilitate the supply chain and promote the storage of vaccines in developing countries.
– The plan is to have it ready by the second half of 2021. Then you can probably keep the vaccine in common refrigerators, Pfizer research chief Mikael Dolsten previously told Svenska Dagbladet.
Russia too – one Vast country with many remote communities: He plans to switch to a freeze-dried variant of his covid Sputnik V vaccine to make it more stable and easier to transport. As it is now, the vaccine must be stored at minus 18 degrees or below to maintain its effect.
Russia has already tested a freeze-dried variant that can handle ordinary cold storage at 2-8 degrees.
– We hope to switch to the freeze-dried form from around February. A large proportion of the doses, if not most, will be in this specific form, Kirill Dmitriev, director of the Russian state investment fund RDIF, which finances and markets the vaccine, tells Reuters.
A man in Moscow is injected with the Russian Sputnik V vaccine.
Photo: Alexander Zemlianichenko Jr / AP
Vaccine lyophilization It is nothing new, but the method has been around for over a hundred years. The first documented lyophilization was done in 1909 with a smallpox vaccine, and today most vaccines that contain a live attenuated virus are lyophilized, such as the mpr vaccine against measles, mumps, and rubella.
In essence, the method is to remove the water so that only a powder remains. When it is time to use it, dissolve the powder in liquid and inject as usual.
– The advantage is that the vaccine becomes more stable. Live weakened viruses need to be lyophilized to last longer, says Peter Stjärnkvist, group director of the pharmacy and biotechnology unit at the Agency for Medical Products.
You’d be surprised if the other companies that develop mRNA vaccines don’t invest in lyophilization like Pfizer. It would not only facilitate transportation and storage in poorer countries, which are often in warmer areas, but also in rich countries where there are not as many extremely cold freezers.
– It should be possible, but of course it is not easy to find the right method and excipients, he says.
It is supported by vaccine researcher Matti Sällberg, who is a professor of biomedical analysis at the Karolinska Institutet.
– If you can freeze-dry the mrna vaccine, that would be very good. It facilitates vaccine deliveries around the world, he says.
The American Modern vaccine is also an mRNA vaccine, requiring extreme cold.
Photo: Ted S. Warren / AP
But lyophilization is not the only technology that results in a stable powder. This is the opinion of Göran Conradson, CEO of the Lund-based company Ziccum, which has developed a method for air drying vaccines. He claims that they have tested the method on several different types of vaccines with good results.
– Pretty much everything works. However, we have not yet run any mrna vaccines because we have not found the material itself, but we have evaluated that it would work, he says.
Air-drying technology was originally developed for drugs that had to be inhaled, but the company saw an opportunity to use it in other drugs and vaccines to make them more stable, long-lasting, and cost-effective.
The company starts with a regular vaccine and adds various sugars that make it more stable, then the vaccine solution is sprayed as tiny drops of water into a tube. The tube is then surrounded by dry air, which causes the water to evaporate and leave a powder.
– It will be like little pearls.
The powder is stored in ampoules and when it is time to use it is mixed in sterile water.
An advantage of air drying is that the vaccine can be stored at room temperature, says the company.
Freeze-dried vaccines must still be in the cold chain.
So far, the company is only conducting studies to verify that the technology does not destroy the vaccine. They have not tested whether the vaccine still has its effect of stimulating antibodies in humans. The company hopes to begin testing vaccines in humans in just over two years or sooner together with its partners.
The goal is to build a plant to dry all kinds of vaccines. The company also has plans to develop an air-dried vaccine to be inhaled or injected through tiny needles in a patch, as the body’s own fluids then dissolve the powder.
– It may take five years in the future before such a product is developed for vaccination.
Peter Stjärnkvist at the Medical Products Agency You don’t know the company’s air drying method, but you think you can use whatever technology you want as long as it works. For the vaccine to be approved, companies must report how they have proceeded, what excipients are in the product, how durable the vaccine is, and be able to demonstrate that the process does not destroy the vaccine.
Are freeze-dried vaccines the future in the fight against coronavirus?
– I think it’s very good that it could be. If you manage to freeze dried mrna vaccines, or in some other way stabilize them so they can withstand normal cold or room temperature, that is a huge plus. Until now, companies have only focused on developing a vaccine, but they will certainly improve, says Peter Stjärnkvist.
Read more:
The challenge: keep the vaccine colder than on planet Mars
This will be the mass vaccination of Swedes against covid-19
The pharmaceutical giants that can vaccinate Sweden
