Thread by @madlori

Hey so I've had some friends/fam ask me, a Science Person, how the new vaccines work. I am not an immunologist, but I speak the Science Language and I'm pretty good at explaining stuff, so here goes. 1/

The new COVID vaccines are not like traditional vaccines, which use dead or denatured infectious agents (viruses, mostly) to prompt the immune system to mount a defense. They're mRNA vaccines, which is a vaccine tech that's been in development for awhile now. 2/

Most of the mRNA work has been done in cancer research, but it's also been investigated for stuff like influenza and Zika. If effective (as it seems to be) it's faster, cheaper, and less risky. Here's how it works. 3/

So your immune system works by recognizing antigens, which are proteins that work like namebadges. Hey, I'm the flu! Hey, I'm chicken pox! Hey, I'm COVID! And the immune system recognizes them, and builds antibodies in response. 4/

Traditional vaccines are like tossing in a dead body wearing the namebadge. The immune system can't tell the body is dead, because it is designed to respond to the namebadge. So it builds the antibodies, so they're already there when a live virus shows up and gets curbstomped. 5/

So what's mRNA? All our cells use it. It's messenger RNA, a little piece of genetic code that takes instructions from your DNA to your cells and tells them what proteins to build. It's a text message from the shop foreman to the production floor, basically. 6/

Viral cells have mRNA, too. And one part of that mRNA is what's telling the virus how to build its unique namebadge. It's easy (well, for certain values of "easy") to sequence a virus and isolate parts, including the mRNA for the namebadge. 7/

So we take that namebadge-building mRNA and encapsulate it, inject it into a healthy person, and it tells your OWN CELLS to build the namebadge and wave it around. This prompts the immune system to swing into action. 8/

Put another way, you're taking a very lifelike COVID disguise and slapping it on your own cells to fool your immune system to Do the Thing without the virus ever being there. It's cutting out the middleman of the virus itself. 9/

Producing little bits of mRNA is a lot faster and cheaper than producing vaccines containing dead virus. It's easier to scale up, too, and probably less likely to produce side effects. If this works, it can be applied to a whole plethora of other diseases and conditions. 10/

So this tech might not only save us from covid, but from a boatload of other bad shit. I hope this helps! 11/11

ETA: Obviously there's a lot more to it. There's also some interesting findings that this type of vaccine may stimulate not only acquired immunity (the kind you get from being infected with something) but innate immunity, which you're born with. Huge if true.