Comment by DoreenMichele | Hacker News Reader

Comment by DoreenMichele | Hacker News Reader

mRNA doesn't change your genetic sequence in any way. It is the exact same intermediate - and temporary - kind of material that your cells generate internally all the time as part of your normal cell processes

The m in mRNA stands for messenger.

I'm failing to find anything I consider to be a succinct explanation in layman's terms (other than the one in the piece under discussion: all that the mRNA vaccines do is to add a dose their own specialized sequence that then makes your normal cell machinery generate that spike protein so that your body learns how to recognize it.).

But from what I gather, mRNA vaccines basically inject your body with a coded recipe for how to manufacture the immune stuff it normally manufactures in reaction to an infection, only without having to first be infected. Not even with a dead version of the virus, as some vaccines use for trying to prompt the body to figure this out more safely than by actually catching the infection.

A few sources I looked at, without feeling satisfied with their explanations:

https://en.wikipedia.org/wiki/Messenger_RNA

https://www.genome.gov/genetics-glossary/messenger-rna

https://www.nature.com/scitable/topicpage/translation-dna-to...

Edit: Thank you to everyone supplying a more accurate explanation in layman's terms. Much appreciated.

> But from what I gather, mRNA vaccines basically inject your body with a coded recipe for how to manufacture the immune stuff it normally manufactures in reaction to an infection, only without having to first be infected.

The mRNA in the Pfizer and Moderna vaccines contains the instructions to make copies of just the spike protein from the outside of the virus. During the short lifetime of the mRNA, your body will follow these instructions and produce these spikes. Alone, this protein isn’t a virus and is pretty much inert.

Then, your body naturally recognizes this protein as a foreign substance and creates antibodies to attack it.

If the real virus enters your body later, your body will already have antibodies that recognize the spike and will immediately start fighting it off, faster than it normally would if you got infected without already having the antibodies.

It’s like a training program for your immune system.

The "central dogma"[1] of biology:

    DNA -> RNA -> Protein

DNA is read sequentially base-by-base (essentially like the read head on a HDD) by a protein called RNA polymerase. As it is reading, it produces RNA. If that RNA is meant to become a protein, it is post-processed to remove various bits and becomes a messenger RNA (mRNA). This mRNA is inserted into another huge protein called the Ribosome[2], and is read 3 bases at a time. Each set of 3 bases corresponds to a single Amino Acid. The string of amino acids produced by the ribosome is a protein.

So the mRNA in the vaccine simply contains the instructions to produce a copy of the spike protein from the COVID-19 virus. When your body produces enough copies of that protein, your immune system takes notice that a foreign protein is floating around and begins the process to recognize and memorize it for future use. (that last part is super simplified).

[1] https://en.wikipedia.org/wiki/Central_dogma_of_molecular_bio...

[2] https://biologydictionary.net/wp-content/uploads/2017/01/Rib...

Nobody tell these guys about the adenovirus platform, which actually does enter the nucleus [1]. (For the avoidance of doubt, it doesn’t tamper with your DNA.)

[1] https://www.medpagetoday.com/special-reports/exclusives/9160...

What it boils down to is the following:

1. Cells contain different organelles that serve different functions.

2. One of the organelles is the Ribosome which exists outside of the nucleus (which contains and protects your DNA) and receives mRNA and tRNA inputs and outputs proteins.

3. The mRNA vaccines contain the RNA necessary for the ribosomes in your cells to manufacture the spike proteins of the virus. The spike proteins are treated as if they were the real deal because your body doesn’t know it is hollow, only that it must be a threat because it doesn’t belong. SARS-CoV-2 shows up with the same spike protein and runs smack dab into the middle of all the antibodies your body produced to target that specific type of threat with that specific spike protein having gone through a dry run before and SARS-CoV-2 gets slaughtered for its efforts.

> But from what I gather, mRNA vaccines basically inject your body with a coded recipe for how to manufacture the immune stuff

That’s not correct. The coded recipe is for covid’s spike proteins. Your body manufactures a bunch of those spike proteins and then has an immune response to them.

Just to clarify the “messenger” thing: mRNA is called like that because it delivers the message (i.e. the instructions to produce a protein) between the genome and the ribosome. The denomination is also useful to distinguish it from other, usually non-coding (meaning “not blueprints for proteins”) types of RNA.

It's not brief but you might enjoy an expert chat about it: https://podcasts.apple.com/us/podcast/vaccines/id1132951842?...

Not exactly. The mRNA fragments are instructions to build pieces of the virus. Your cells execute the mRNA instructions, build virus fragments, and _then_ the immune system notices all these unknown fragments and learns how to destroy them.

Technically the cells manufacture the spike protein and your body will develop neutralizing antibodies to the spike protein, the cells will also display the antigen (spike protein) on the surface of the cells in an MHC-antigen complex. That'll trigger CD4+ and CD8+ T-cells to also go into action. Some of the cells will be transported to lymph nodes and the gut for processing by the immune system. CD8+ cells will learn to recognize the MHC-antigen on the surface of cells and kills the "infected" cells.

Then next time around B-cells and T-cells are primed from all this target practice and its a lot easier, even if the neutralizing antibodies wane.

It’s more that they contain coded instructions to create a protein which the immune system can then react to, and learning to react that protein confers the ability to react to the virus (which has that protein in its surface)

I & others tried about 6 months ago in this thread that asked a similar Q.

https://news.ycombinator.com/item?id=25319117

The mRNA recipe is for a distinctive spike protein on mainstream COVID, your cells unwittingly produce this spike protein, then your immune system says "what's this garbage?" and attacks it.

They are the recipe for one piece of the virus (which is important to its function, so hopefully among the parts least subject to mutation), and then your cells that get vaccine in them make the foreign protein, which then causes the usual immune response to foreign proteins. The difference from what you said is that the code in the vaccine is for the foreign stuff, and the immune stuff comes from your immune system.

Reply on news.ycombinator.com