Summary info on how the new mRNA Covid-19 vaccines (Pfizer, Moderna) work— no DNA reprogramming, no microchips:

Short summary of how the US approved mRNA Covid vaccines work (Pfizer, Moderna)

With my work in Covid-19 related AI, I frequently get asked about the various covid vaccines, both approved and pending. Thus, I’m writing this article to provide a useful summary of the current mRNA vaccines, and will likely add another one on what’s pending — how they work, how and why they have been shown to be safe, and what’s potentially coming for vaccines in 2021.

US approved vaccines — Pfizer and Moderna — mRNA platform:

The basic path from mRNA to immune response (original image JMarchn, wikimedia) with my crude path additions. mRNA introduced to the bloodstream via injection (purple circle at top), picked up by dendritic cells that read the message and produce Covid-19 spikes on their surface. Immune cells then learn about the spike (light blue boxes) generating a prepared memory for future (actual) Covid-19 challenges.

The only two approved vaccines at the time of this writing in the US are both based on the same core technology- mRNA, or messenger RNA.
For background, your cells produce mRNA all day, every day. They are the ‘post-it’s for intra cellular communication of what proteins the cell needs to build. Normally these messages come from the nucleus of the cell, where the DNA is read in various sections, and then mRNA copies of that info are sent out for production. For vaccines, the process has been updated to allow the mRNA to be introduced via an injection and then leverage your bodies existing protein production process.

To make an mRNA vaccines, the message for how to make a Covid-19 spike protein is produced, and then wrapped into a lipid, protective layer. The lipid particles are then added to a salt water solution to match the salinity and PH of human blood and you have your vaccine ready to go. (for Moderna, the ingredients besides mRNA and lipids are: tromethamine, tromethamine hydrochloride, acetic acid (PH buffer), sodium acetate (salt), sucrose).

Upon injection, dendritic cells (among others) uptake the lipid wrapped message, read the message, and then produce Covid-19 spikes on their surface. Your immune system interacts with the Covid spikes, and prepares the process for making antibodies to it.

With the job done of providing this info to the immune system, the mRNA message is destroyed in the same manner as other mRNA’s from the cell nucleus are routinely read and removed.

Most importantly though, with the Covid response learned and prepped by your immune cells, it means that future interactions with an actual (real) Covid-19 viral challenge can be met and dismissed as your body is know aware and on the lookout for Covid spikes, rendering effective immunity.

This head start means your body now has the jump on dealing with Covid in the future, versus the virus having a head start on first introduction.

That, in summary form, is how mRNA vaccines work.

mRNA advantages:

The mRNA approach thus provides multiple advantages including:

* non-infectivity (it’s a message for how to make a protein, not a virus, using your cells existing protein building infrastructure),
* no need for adjuvants (ingredients designed to poke the immune system to make sure it remembers the vaccine info),
* ability for rapid production (a simple message is encoded over and over, no need to grow viral carriers in eggs, purify them, etc.)

In fact, the mRNA message to encode the Covid spike protein only required two days for Moderna to make.

With the above understanding, you can also see that many conspiracy theories such as the mRNA vaccines will ‘reprogram’ your DNA are bunk. Unlike traditional vaccines, the mRNA never enters the cell nucleus, where your DNA is housed, and the mRNA is destroyed after the message is read, just like all other thousands and thousands of mRNA message produced in all your cells, every day.

The main negative for this approach is that since mRNA is designed to be read and then destroyed, mRNA is inherently very, very fragile. This is why both vaccines require varying degrees of extremely cold storage to ensure it doesn’t degrade. mRNA in the outside world would degrade within minutes, meaning it’s no longer a readable message and thus worthless as a vaccine.

Safety profile:

Both mRNA vaccines have gone through the required two month, post vaccination review period, along with the phase 1, 2 and 3 trials. From hard experience, two months is the primary window where any side effects would show.

In addition, while these are the first vaccines to be approved based on mRNA, mRNA research is over 30 years old, going back to the Salk institute in 1989. The core breakthrough was in 2005, when Kariko and Weissman figured out how to get the mRNA into cells without being destroyed along the way by the bodies immune cells. This was the core technology which inspired the creation of Moderna and BioNTech (Pfizers partner).

Thus, there is in fact a long background of R&D related to mRNA vaccines. More importantly, with the testing of over 70,000 people, a near 95% efficacy rate means they are potentially among the most successful vaccines ever produced. The normal threshold for approval is 50%.


Both of the approved mRNA vaccines have shown an excellent safety profile as well efficacy. Hopefully, with the basic understanding of how mRNA vaccines work provided above, you’ll be able to realize that many of the crazy theories about these vaccines, are …crazy and spread based on lack of people’s knowledge about this new type of vaccine.

The speed of bringing these to market is not the result of cutting corners but rather because much of the research for the mRNA platform has been ongoing since 2005, and the relative ease of producing a message, instead of a traditional viral carrier.

In a future article I’ll cover the more traditional vaccine candidates (AstraZeneca/Oxford) and how those work, as these do introduce a viral carrier and do interact with a cells nucleus. In addition, I’ll hopefully be able to write up a summary of one of the newest and interesting vaccines based on nano-particles by University of Washington. This is basically a tiny ball of 60 covid synthetic spike proteins that generate an extraordinary immune response (10x) while not even needing to enter your cells at all.

Further info:

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