For a smart cookie your Q-factor is unusually stronque..
This inauguration speech:
http://historymatters.gmu.edu/d/5057/
It's one thing to be fearful of fear itself: Though a good point in some cases, fear is arguably part of self preservation and therefore also has it's benefits.
Yet the manipulation of whomever is trying to whip up that fear is far far worse and has nothing to do with what you want for yourself.
It makes one, for a totally arbitrary example, storm government buildings in instigated outrage for, when you really think of it, no good reason with zero benefits for yourself.... oh the sacrifice?
Your slippery-slope of that keyword-chain: "darwin", "eugenics", "nazi's" and "vaccine"-terror to have enough "fireworks" to invoke that "25th" in one short reply is one indicator.
I have no illusion to convince you of anything, but I can try to shine my own light on it with obviously more words - because it simply requires some arguments and not catchphrases. That's the thing with arguing against fear and propaganda-for-the-likez... hence there's more material to cherry-pick your counter "argument".
As with many of my replies here, it's mostly for my own exercise.
Darwin's fitness is not about having the top of qualities, where eugenics leads to x-men like qualities.
Fitness is about having the most sufficient "tools" to survive for the least amount of energy-requirement and maintenance. This "species"-thing as a whole is just a tool.
For example: A full spectrum eye is useless when living in the dark, better grow some hyper sensible tentacles or have a bio-illuminated limb.
When you really think about that nazi-fetishism you mentioned: The end-game of that "filtering" for the purest thing (because there's 'surely' no purest thing than themselves) is simply to go f*ck themselves... literally that is!
Many may have seen/know some of the consequences of inbreading: In short: because of a lack of DNA variation... they'll become weak and fragile!
Hence the conclusion: this "pure race"-nazi fetish to keep the group "strong" is a false premise.
How do we know? Science!
https://en.m.wikipedia.org/wiki/Inbreeding_depression
Can we see the effects? Shortcut version: Many are familiar with "small-town"-relations.
A theory to overcome? Darwin's survival of the fittest.
How does that work? Having variation and diversity to 'find' and recombine the DNA-programming to generate biological tools that gives an edge in the environment, not because it is liked.
You may select for it, if our species as a whole is willing to drive itself in that direction, but then you get those funny features like the dancing paradise birds and peacock tails - beautiful but useless.
It steals biological energy from other typical features... like the brain and its supposed container for intelligence.
Is this diversity universal? Yes. For a totally random example: You'll find that missing collection-piece not by attending only your local club, but by going to a variety of larger gatherings further away.
It's one example where a shared lack of self-worth is used to be made believe to belong at the top of the world which leads to willingness to do the lowest things to keep that image alive.
In short, the solution is found in variation.
For the mRNA part of the virus: A nonfunctional part is used to instruct your immune system to do some pattern recognition....
It's foreign material by definition. You probably know the feeling of those pesky little flies that dies and smears out in the corner of your eye when your on a bike with head wind in summer....foreign material: microbal, bacterial, genetic...
Some parts of your immune system is constantly creating patterns as like it's a random number generator. But that's how it's (more or less) able to fight off foreign unknown material. If it "works", then that match replicates. You may even get a fever to speed up that replication process, it's a good thing for a short while.
In short, the solution is found in variation... for the same reason as earlier.
Likely you'll find more in the following wiki and its references:
https://en.m.wikipedia.org/wiki/Adaptive_immune_system
A vaccine based on mRNA just helps your immune system in pattern-matching.
As a non-helping comment: Sure they can inject you with heroin (for example) to make you a returning 'costumer' - how would you know before if not for too late?
Another viewpoint that may help: Your computer virus scanner with its virus database is almost similar to that immune system... With a piece of (scanning) software it tries to match data (a distinguishing part of the virus software) in your system or inside files. There is simply not enough data (or heuristically tangled up) to recreate a working software-part of whichever virus it tries to detect. Even when you'd take that data, put it into an executable, and actually started it, it would likely give an error. Best case is when that virus scanner would kick in again and quarantine your created program.
You'll have to find for yourself a trusted source to verify this story.
Short story, long: No extra ear for you!