June 26, 2022

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The technical divergence behind the breakthrough COVID-19 vaccines

The technical divergence behind the breakthrough COVID-19 vaccines

The technical divergence behind the breakthrough COVID-19 vaccines, Reference News Network reported on November 22 that the British “Financial Times” website published a report entitled “The Secret Ingredient Behind the Breakthrough New Coronavirus Vaccine” on November 20, with the generality as follows:

The two breakthrough vaccines that use the same revolutionary technology are very effective in preventing the new coronavirus, but the difference in the design of the two vaccines has affected the speed of increase in production and the way of distribution.

These two vaccines-one is produced by Moderna in the United States, and the other is developed by Pfizer in cooperation with the German biotech company-have shown an effective rate of more than 94% in clinical trials.

The core of these two vaccines is messenger ribonucleic acid (mRNA). mRNA is composed of about 2,000 biochemical genes. It transmits instructions to the immune system of vaccinators to recognize and fight against the new coronavirus infection.

Zoran Kish, a researcher at Imperial College’s Future Vaccine Manufacturing Center, explained that Moderna’s vaccine uses 100 mg of RNA per injection, while Pfizer-Biotech’s vaccine uses only 30 mg. Easier to manufacture and less expensive.

This should allow Pfizer-Biotech to increase production faster than their competitors. The immunologist added that it is unclear why Moderna’s vaccine requires a larger dose of RNA.

“It is very difficult for outsiders to know exactly what is in the vaccine,” said Alexander Edwards, a professor of biomedical technology at the University of Reading in the United Kingdom. “But its composition can have a significant impact on the efficacy.” Despite the two vaccines The RNA is the same, but there may be slight differences in its genetic sequence, which makes Pfizer-Biotech’s vaccine very effective in a smaller dose.

In the vaccines of Moderna and Pfizer-Biotech, RNA is encapsulated in “lipid nanoparticles” to protect its fragile genetic instructions. Scientists say that the composition of the two vaccine lipid nanoparticles is slightly different, which will have many effects.

“This kind of nanoparticles can magically unlock recipes,” Professor Edwards said. “You may have a list of recipes, but you don’t know how they combine to produce particles of the right size and shape. This is very similar to food production— —You may know the ingredients for Heinz Ketchup, but you can’t produce them.”

Pfizer-Bio New Technology Co., Ltd. obtains lipid nanoparticles from a professional Canadian company, Arquetas, and Moderna has developed its own lipid technology.

Mike Watson, former head of Moderna’s vaccine department, said: “The process and challenge of developing lipid nanoparticles is to combine lipids with different physical properties with an effective and stable RNA.”

Both vaccines need to be refrigerated to keep the lipid nanoparticles in good shape and prevent mRNA degradation. However, Moderna’s vaccine is stable enough to be stored at minus 20 degrees Celsius-the temperature of a standard home or low-temperature refrigerator-for 6 months, while Pfizer-Biotech’s vaccine needs to be stored at minus 70 degrees Celsius. Under storage and transportation.

In this way, once the regulatory approval is obtained, Moderna’s vaccine will be “easier to distribute and cheaper,” said Dr. Kish of Imperial College London.

Pfizer-Biotech must design a special “ultra-low temperature transport box”, which can be stored at that temperature for 15 days after it is regularly loaded with dry ice. Each “ultra-low temperature transport box” has a thermometer connected to a global positioning system that can track temperature and location throughout its distribution network. Even so, temperature requirements will make it difficult to distribute vaccines in areas without adequate cold chain storage capacity, such as Africa and Asia.

In contrast, the vaccine being developed by the University of Oxford and AstraZeneca Pharmaceuticals in the UK can be stored for months without freezing. The Oxford University vaccine does not use mRNA technology, but attaches the new coronavirus spike protein gene used to trigger an immune response to harmless respiratory viruses, which will take them into human cells. Sara Gilbert, the head of the Oxford team, said that its vaccine can remain stable in a normal refrigerator at 2 to 8 degrees Celsius.

The difference in lipid composition between Pfizer-Biotech and Moderna may also affect how each vaccine works. Brian Ferguson, an immunology researcher at the University of Cambridge in the United Kingdom, said: “Lipid nanoparticles will have some synergistic activities, and vaccination will produce a little inflammation, which will help the immune system produce antibodies and T cells against the new coronavirus.”