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  • In the 20th century, most vaccines took well over a decade to research, test, and produce.

  • But the vaccines for COVID-19 cleared the threshold for emergency use in less than 11 months.

  • The secret behind this speed is a medical technology that's been developing for decades: the mRNA vaccine.

  • This new treatment uses our body's existing cellular machinery to trigger an immune response, protecting us from viruses without ever experiencing an infection.

  • And in the future, this approach might be able to treat new diseases almost as quickly as they emerge.

  • So how do these revolutionary vaccines work?

  • The key ingredient is in the namemRNA, or messenger ribonucleic acid, is a naturally occurring molecule that encodes the instructions for producing proteins.

  • When our cells process mRNA, a part of the cell called the ribosome translates and follows these instructions to build the encoded protein.

  • The mRNA in these vaccines works in exactly the same way, but scientists use the molecule to safely introduce our body to a virus.

  • First, researchers encode trillions of mRNA molecules with the instructions for a specific viral protein.

  • This part of the virus is harmless by itself, but helpful for training our body's immune response.

  • Then, they inject those molecules into a nanoparticle, roughly 1,000 times smaller than the average cell.

  • This nanoparticle is made of lipids, the same type of fatty material that forms the membrane around our cells.

  • But these lipids have been specially engineered to protect the mRNA on its journey through the body, and assist its entry into the cell.

  • Lastly, the final ingredients are added: sugars and salt, to help keep the nanoparticles intact until they reach their destination.

  • Before use, the vaccine is kept at a temperature of -20 to -80 degrees Celsius to ensure none of the components break down.

  • Once injected, the nanoparticles disperse and encounter cells.

  • The lipid coating on each nanoparticle fuses with the lipid membrane of a cell and releases the mRNA to do its work.

  • At this point, we should note that while the vaccine is delivering viral genetic material into our cells, it's impossible for this material to alter our DNA.

  • mRNA is a short-lived molecule that would need additional enzymes and chemical signals to even access our DNA, let alone change it.

  • And none of these DNA-altering components are present in mRNA vaccines.

  • Once inside the cell, the ribosome translates the mRNA's instructions and begins assembling the viral protein.

  • In COVID-19 vaccines, that protein is one of the spikes typically found on the virus's surface.

  • Without the rest of the virus, this lone spike is not infectious, but it does trigger our immune response.

  • Activating the immune system can be taxing on the body, resulting in brief fatigue, fever, and muscle soreness in some people.

  • But this doesn't mean the recipient is sickit means the vaccine is working.

  • The body is producing antibodies to fight that viral protein, that will then stick around to defend against future COVID-19 infections.

  • And since this particular protein is likely to be found in most COVID variants, these antibodies should reduce the threat of catching new strains.

  • This approach offers significant advantages over previous vaccines.

  • Traditional vaccines contain weakened versions of live viruses or amputated sections of a virus, both of which required time-intensive research to prepare and unique chemical treatments to safely inject.

  • But mRNA vaccines don't actually contain any viral particles, so they don't have to be built from scratch to safely adjust each virus.

  • In fact, every mRNA vaccine could have roughly the same list of ingredients.

  • Imagine a reliable, robustly tested vaccine that can treat any disease by swapping out a single component.

  • To treat a new illness, researchers would identify the right viral protein, encode it into mRNA, and then swap that mRNA into the existing vaccine platform.

  • This could make it possible to develop new vaccines in weeks, giving humanity a flexible new tool in the never-ending fight against disease.

  • But where do vaccines get started? Watch this video to travel back to 1796, when an eight-year-old boy changed the course of history.

  • Or, get the answer to a pressing question: When exactly is a pandemic over?

In the 20th century, most vaccines took well over a decade to research, test, and produce.

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B2 UK TED-Ed mrna protein viral immune covid

How the COVID-19 vaccines were created so quickly - Kaitlyn Sadtler and Elizabeth Wayne

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    OolongCha posted on 2021/10/09
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