This Wednesday, the United Kingdom gave emergency authorization to the coronavirus vaccine developed by Pfizer, anticipating the United States to become the first western country to approve it.
The Pfizer Vaccine is in its last phase of studies and showed an effectiveness of 95% in all age groups. The United Kingdom requested more than 40 million doses of the vaccine that will serve to inoculate 20 million people.
In a media meeting on Downing Street, Dr. June Raine, head of the Regulatory Agency for Medicines and Health Products stated that for the approval of the vaccine “there were no shortcuts” and it”meets the strictest safety, effectiveness and safety criteria”.
The UK’s approval of the vaccine pressures will intensify on the US auhotirities to speed up the approval procedures for the vaccine to counter a disease that has already killed more than 1.4 million people.
The FDA is already under fire from the White House for not rushing to approve the Pfizer vaccine as well as the Moderna vaccine, which, unlike the Pfizer vaccine, does not need to be refrigerated in a -80 degree celcious container to be preserved.
Although the approval of the Pfizer vaccine in the United Kingdom would help the rapid distribution of the vaccine in the countries that acquire it, as well as among the members of the Commonwealth, until the regulators of the European Union and the United States do not approve the vaccine, a massive distribution is still far from being a reality.
The strict conditions of refrigeration and storage of the Pfizer vaccine could impose severe restrictions on its distribution, which according to British contingency plans would first be distributed among nursing homes and institutions in the care of the elderly.
How does the Pfizer vaccine works?
Both the Pfizer and Moderna vaccines were designed using Messenger RNA (mRNA) technology. mRNA medicines, unlike traditional vaccines, are not small molecules, nor are they biological products such as recombinant proteins and monoclonal antibodies, which were the foundation of the biotechnology industry.
Like DNA, ribonucleic acid (RNA) functions as a chain of the genetic code that transmits essential information for the functioning of our systems, such as protein synthesis (a process in which our cells create essential proteins for our body to survive).
MRNA drugs are a set of genetic instructions that are passed on to cells in the body indicating that they must make proteins to prevent or combat diseases like COVID-19 in this case.
Through a process known as transcription, a copy of the mRNA from a DNA sequence is made to create the protein. This copy (the mRNA) travels from the nucleus of the cell to the cytoplasm, which is in charge of housing ribosomes.
Ribosomes are like nano-machines (organelle) in the cells responsible for transforming amino acids into protein. In a process known as “translation,” ribosomes “read” mRNA and follow its instructions to create the necessary proteins the body requires to prevent contagion.
Why Pfizer vaccines mut be stored at Antartica’s temperature?
Vaccines based on the concept of mRNA are an extremely new technology, to begin with, and a vaccine of this type has never been approved in the history of the Food & Drugs Administration (FDA).
Being a new technology, mRNA is still highly unstable and can be easily destroyed, so it requires treatments to stabilize it; among them, keeping it in extremely cold temperatures and covering it in a layer of lipid nanoparticles to avoid being affected.
The first step, Liu says, is to modify the mRNA nucleosides, the “building blocks” of the RNA vaccine. “They have used modified versions because they are more stable,” she says. This would be like changing the chocolate recipe so it is not so sweet.
The next step was to use lipid nanoparticles, which, explains Liu, “is like putting chocolate in a layer of candy: you have a coating like M&M, so that chocolate does not melt.”.
But even with the stabilized components and lipid coating, mRNA could still easily crumble, making the vaccine frozen. “Everything happens more slowly as the temperature drops,” says Liu. “Then your chemical reactions, the enzymes that break down RNA, will happen more slowly. It’s the same idea as freezing food to keep it from spoiling.” Liu stated.
Although Liu is unaware of the reason why the Moderna vaccine does not require refrigeration since both formulas are still confidential, she thinks that it is because Moderna has a little more experience than Pfizer working with this technology, since Moderna has already developed 10 candidates for vaccines previously using this technology.