The first COVID vaccine launched in the United States, that of Pfizer and BioNTech, is an mRNA vaccine. The second will probably be the same: Moderna’s vaccine is pending consideration this week. We’ve never had a commonly used mRNA vaccine before, so you’re not alone if you’re wondering what the hell this technology is and if it has anything to do with DNA.
To answer the most frequently asked questions: No, it doesn’t change your DNA. No, it ‘s not an unproven technology (it really is he has been working for decades). And the CDC has done it a data sheet here with the basics you need to know about new technology.
But here’s the very short version: the vaccine’s mRNA contains instructions for telling our body how to build a coronavirus ear protein. As soon as we do, our immune system flips, as it is supposed to, and creates antibodies against the ear protein. The mRNA is destroyed shortly after injection, but the antibodies stick around. Then, they will be able to recognize the real virus if we find it free.
Do you want the longest and most detailed version? Here we come.
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Our cells contain DNA and produce mRNA continuously
Let’s start with a quick update on what it means to have genetic material. The DNA we have, as humans, is contained in (almost) every cell in our body. It includes instructions for everything a cell may need to do. Processing food, growing more cells, releasing hormones – anything that happens in the body happens because the cells follow recipes encoded in your DNA.
Every time our cells use one of these recipes, we must first copy the information from the DNA. This copy, instead of being another piece of DNA, is a slightly different type of molecule called RNA. (It’s like DNA is a collection of reference books in a library. You can’t consult the book because it has to stay in the library, but you can write the information you want in a notebook and take it ). this with you. The notebook is RNA.)
Copying DNA to make RNA is a process called transcription, and the next step is often translation: using RNA instructions, now called mRNA, to make a protein. Proteins make up a large part of our body structure, and small protein-forming machines perform almost all of our bodily functions. We are constantly manufacturing mRNAs and using them to make proteins. All the time.
The “m” in mRNA means “messenger” and refers to the type of RNA we are talking about here, the ones that carry information from DNA to the machinery to make proteins. (There are many other RNAs in the world, but we don’t stray too far).
The wild coronavirus contains RNA instructions for constructing
Before we talk about the vaccine, let’s look at how the virus that causes COVID, SARS-CoV-2, works in nature. Viruses are smaller and simpler than any of our cells and many scientists will argue that they are not “alive” in the same way that humans or even bacteria are.
A virus is made up of proteins, sometimes wrapped in a envelope of lipids (fats). Proteins make up proteins pointed ball shape of the coronavirus. The red clouds in this iconic illustration you’ve seen are the tip proteins, but more on them later. There are 28 more proteins which form the rest of the virus.
And inside that pointed ball? There is a single, long strand of RNA. This RNA is the genome of the virus and contains instructions for building the 29 proteins of the virus itself.
When the virus infects our cells, our own protein-making machinery translates the viral RNA and makes the proteins it requires. We have been deceived; we just made a lot of parts of the virus. These parts become new viruses, each with its 29 proteins and a new copy of its RNA, and then go out into the world to infect more cells.
(Again, I give you a very rational summary of what is happening; this Nature article describes the coronavirus life cycle in all its nerdy details).
MRNA vaccines instruct our cells to build ear protein
A traditional vaccine would include at least one protein from the virus or bacterium it is targeting, possibly an entire virus that has been inactivated or weakened so that it cannot replicate. But an mRNA vaccine does things differently.
This vaccine does not provide us with any protein, just a small lipid bubble (similar to the micelles in the micellar water, the makeup cleanser) that contains RNA with instructions on how to make the ear protein. These instructions are even formatted as a nice human-style mRNA, rather than the special and complicated structure of viral RNA.
With these instructions, our cells can make the spike protein (a lot of these red clouds), but that’s it. The other 28 proteins are absent. Therefore, we will not make any viruses by mistake.
Our immune system can respond to ear protein
After making spike protein, cells can put spike proteins on their exteriors, where cells in the immune system can interact with them. Our immune system recognizes cutting-edge proteins as alien and not part of ourselves and creates an immune response against them.
The immune response may include pain, fever, or fatigue. But you are not sick; your immune system only responds to the ear protein and is preparing to be able to recognize it in the future.
The mRNA in the vaccine disappears quickly
The mRNA of the vaccine does not stick. Just as our cells always make mRNA, they also constantly destroy it. The mRNA is a temporary messenger, which is used and focused within seconds of being created.
Although RNA and DNA are nucleic acids, and both are “genetic material” in a sense (DNA is our genetic material, RNA is the genetic material of the virus), mRNA cannot being part of our DNA and doing nothing to change our DNA. It is a different type of molecule, in a different part of the cell.
Why mRNA vaccines?
Various types of vaccines are being tested to detect COVID. Many use traditional technologies, such as modifying a cold virus so that it cannot replicate, and therefore also include a coronavirus ear protein.
But mRNA vaccines work especially well in this situation because they can be done so quickly. If you want to make a lot of doses of a vaccine, you have to grow these viruses in some way. The flu vaccine is famous has been grown in chicken eggs, for example.
MRNA vaccines are faster because you don’t need any cell type to make them. Technology for mRNA vaccines has been in operation for many years and 2020 is the time to shine. If you want to learn more about how the vaccine developed so quickly, here we have an explanation.