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One question I have about mRNA vaccines that I haven't been able to find the answer to through my own searching: how is the mRNA delivered to the cell? All the

One question I have about mRNA vaccines that I haven't been able to find the answer to through my own searching: how is the mRNA delivered to the cell? All the articles I read say that the mRNA is "taken up by the cell", but what is the mechanism? Do cells naturally just absorb free-floating mRNA? Or is a modified virus used to inject the mRNA?

known 6y ago
In both the Moderna and Pfizer-BioNTech vaccines the RNA is encapsulated in “lipid nanoparticles”. These microscopic droplets of oily liquid — about 0.1 micron in diameter — enclose and protect the fragile genetic instructions as they are manufactured, transported and finally injected into people. https://archive.is/6dxTg https://archive.is/6dxTg
- dfsegoat 6y ago
  So it's naked mRNA wrapped in oil, basically?
  - known 6y ago
    “The lipid nanoparticles have some adjuvant activity, providing a little inflammation with the vaccination that helps the immune system to make antibodies and T-cells that target the Sars-Cov-2 virus,”
    - floatingatoll 6y ago
      Itchy oil, then.
dfsegoat 6y ago
It appears there are a few different approaches, described here: https://en.wikipedia.org/wiki/RNA_vaccine#Delivery https://en.wikipedia.org/wiki/RNA_vaccine#Delivery Viral vectors were the ones I was familiar with. I am not sure which one the Pfizer vax uses, however.
Kliment 6y ago
Very very simplified: Basically, you have a blob of fat that the mRNA sits in. The fat sticks to the cell, merges with the cell membrane and the mRNA pokes into the cell. It's not a modified virus, it's a much simpler structure but it has a similar mechanism. It's much simpler in that it can't replicate itself or do much else. It's literally just the code for a protein that's found on the surface of the covid virus, in a blob of fat. That's for the BioNTech/Pfizer vaccine. Other vaccines, such as the Oxford/AstraZeneca one do use a modified virus.
- abacadaba 6y ago
  So no spike protein needed? Safe to assume that in time these will evolve into new forms of fat-embeded rna virus which no living being has immunity to?
  - dogma1138 6y ago
    The mRNA contains the spike protein or at least a sufficient part of it for the immune system to recognize, as well as other genes.
  - Kliment 6y ago
    No, they won't. They can't survive for long enough inside the body, and are even less durable outside.
excerionsforte 6y ago
John Campbell talks about that here in a digestible way: https://youtu.be/smm_ZvJqJk4?t=438 https://youtu.be/smm_ZvJqJk4?t=438
dbsmith83 6y ago
https://www.acsh.org/news/2020/10/21/how-pfizers-rna-vaccine-works-15104 https://www.acsh.org/news/2020/10/21/how-pfizers-rna-vaccine... Essentially the mRNA is packaged into a lipid, which the body's cells can uptake thru its phospholipid bilayer

known 6y ago

In both the Moderna and Pfizer-BioNTech vaccines the RNA is encapsulated in “lipid nanoparticles”. These microscopic droplets of oily liquid — about 0.1 micron in diameter — enclose and protect the fragile genetic instructions as they are manufactured, transported and finally injected into people. https://archive.is/6dxTg https://archive.is/6dxTg

dfsegoat 6y ago
So it's naked mRNA wrapped in oil, basically?
- known 6y ago
  “The lipid nanoparticles have some adjuvant activity, providing a little inflammation with the vaccination that helps the immune system to make antibodies and T-cells that target the Sars-Cov-2 virus,”
  - floatingatoll 6y ago
    Itchy oil, then.

dfsegoat 6y ago

It appears there are a few different approaches, described here: https://en.wikipedia.org/wiki/RNA_vaccine#Delivery https://en.wikipedia.org/wiki/RNA_vaccine#Delivery Viral vectors were the ones I was familiar with. I am not sure which one the Pfizer vax uses, however.

Kliment 6y ago

Very very simplified: Basically, you have a blob of fat that the mRNA sits in. The fat sticks to the cell, merges with the cell membrane and the mRNA pokes into the cell. It's not a modified virus, it's a much simpler structure but it has a similar mechanism. It's much simpler in that it can't replicate itself or do much else. It's literally just the code for a protein that's found on the surface of the covid virus, in a blob of fat. That's for the BioNTech/Pfizer vaccine. Other vaccines, such as the Oxford/AstraZeneca one do use a modified virus.

abacadaba 6y ago
So no spike protein needed? Safe to assume that in time these will evolve into new forms of fat-embeded rna virus which no living being has immunity to?
- dogma1138 6y ago
  The mRNA contains the spike protein or at least a sufficient part of it for the immune system to recognize, as well as other genes.
- Kliment 6y ago
  No, they won't. They can't survive for long enough inside the body, and are even less durable outside.

excerionsforte 6y ago

John Campbell talks about that here in a digestible way: https://youtu.be/smm_ZvJqJk4?t=438 https://youtu.be/smm_ZvJqJk4?t=438

dbsmith83 6y ago

https://www.acsh.org/news/2020/10/21/how-pfizers-rna-vaccine-works-15104 https://www.acsh.org/news/2020/10/21/how-pfizers-rna-vaccine... Essentially the mRNA is packaged into a lipid, which the body's cells can uptake thru its phospholipid bilayer